Eastern Orthodox and Roman Catholic Christianity: Key Differences Explained

Eastern Orthodox and Roman Catholic Christianity: Key Differences Explained

Eastern Orthodox and Roman Catholic Christianity share far more history, theology and worship than their centuries of separation sometimes suggest.

Both traditions trace their origins to the early Christian Church.

Both confess the Trinity.

Both teach that Jesus Christ is fully divine and fully human.

Both have bishops, priests and deacons.

Both celebrate the Eucharist as a sacrament rather than treating it as merely symbolic.

Both baptise infants, honour saints, venerate Mary, maintain monastic traditions and understand episcopal ministry through the idea of apostolic succession.

Yet they have remained outside full communion with one another for centuries.

The reasons are historical as well as theological.

Questions surrounding the authority of the Bishop of Rome, the wording of the Nicene Creed, the relationship between local churches, original sin, later Catholic dogmas and differing patterns of worship all contributed to separation between the Christian East and West.

Some popular descriptions exaggerate the differences.

Others minimise them.

The most accurate picture is more complicated.

Eastern Orthodox and Roman Catholic Christians share much of the theological inheritance of the first millennium while disagreeing about how particular doctrines developed and how authority should function within the Church.

This article explains those similarities and differences without assuming that either tradition can be reduced to a simple list of opposing beliefs.

For a broader introduction to the Eastern tradition itself, see Orthodox Christianity: History, Beliefs and Traditions Explained.

Eastern Orthodox vs Roman Catholic Christianity at a glance

This table simplifies traditions that contain significant internal variation, but it provides a useful starting point.

Shared Christian origins

Orthodox and Catholic Christianity did not begin as two separate churches.

For many centuries, Christians in Rome, Constantinople, Alexandria, Antioch, Jerusalem and elsewhere understood themselves as belonging to one Church despite differences in language, liturgy and local custom.

The five historic centres later commonly described as the Pentarchy were:

• Rome
• Constantinople
• Alexandria
• Antioch
• Jerusalem

Rome occupied a particularly important position.

Eastern Christians recognised the Bishop of Rome as holding primacy among the major episcopal sees.

The later disagreement concerned what that primacy meant.

Was the Bishop of Rome the first bishop within a communion of churches?

Or did the Pope possess universal authority over every Christian bishop and local church?

That question became one of the principal fault lines between Orthodoxy and Catholicism.

The first millennium

During the first thousand years of Christianity, the Eastern and Western churches participated in common councils and shared the same fundamental creedal inheritance.

The first seven Ecumenical Councils remain recognised by Eastern Orthodoxy and Roman Catholicism.

These councils addressed questions including:

• the divinity of Christ
• the Trinity
• the relationship between Christ's divine and human natures
• the title Theotokos for Mary
• the veneration of icons

This common period is important because Orthodox-Catholic disagreements developed within a Church that already possessed considerable theological unity.

The eventual separation therefore cannot be understood as Christianity splitting into two completely unrelated religions.

Cultural differences between East and West

Differences developed gradually.

The Christian East was heavily Greek-speaking.

The Christian West increasingly used Latin.

Different theological vocabularies emerged.

Political structures also changed.

After the collapse of imperial authority in Western Europe, the Bishop of Rome acquired an increasingly important political as well as religious role.

Constantinople remained the capital of the Byzantine Empire.

Western and Eastern Christians also developed different liturgical practices.

These differences were not necessarily regarded as church-dividing at first.

Over centuries, however, cultural distance made theological disputes more difficult to resolve.

The Great Schism

The year 1054 is traditionally associated with the Great Schism between Eastern and Western Christianity.

In that year, representatives of Pope Leo IX placed a sentence of excommunication against Patriarch Michael Cerularius of Constantinople and others.

The patriarch and his synod responded with a similar condemnation.

It is misleading, however, to imagine that millions of Christians suddenly woke up the following day belonging to two clearly separated churches.

The division developed gradually.

The Catholic and Orthodox churches themselves later acknowledged that the 1054 condemnations were directed primarily at particular individuals rather than formally excommunicating entire churches.

In 1965, Pope Paul VI and Ecumenical Patriarch Athenagoras I jointly removed the historic excommunications from memory and acknowledged that subsequent separation had gone far beyond what those involved in 1054 had originally intended.

This did not restore full communion, but it marked an important change in Catholic-Orthodox relations.

The Fourth Crusade

If 1054 represents one symbolic moment in the schism, 1204 was arguably more damaging emotionally.

During the Fourth Crusade, Western crusaders captured and sacked Constantinople.

Churches were looted.

Relics and treasures were taken.

Violence was committed against the population of what was supposed to be a Christian city.

A Latin political regime was subsequently established in Constantinople.

The memory of 1204 deeply damaged relations between Byzantine Christians and the Latin West.

The event reinforced the idea that the division was not simply about abstract theology.

Political rivalry, war and mistrust played enormous roles.

Authority of the Pope

The most fundamental continuing disagreement between Eastern Orthodox and Roman Catholic Christianity concerns the authority of the Pope.

Catholic teaching understands the Bishop of Rome as the successor of St Peter with a universal ministry in the Church.

The Pope possesses authority that extends throughout the Catholic Church.

Eastern Orthodoxy does not accept universal papal jurisdiction in this form.

Orthodox Christians generally acknowledge that Rome occupied a special place in the ancient Church.

The disagreement concerns the nature of that primacy.

Orthodox ecclesiology normally describes the Church through the relationship of bishops and local churches gathered in council.

The Ecumenical Patriarch of Constantinople holds a primacy of honour within contemporary Eastern Orthodoxy and is commonly described as first among equals.

But he does not govern all Orthodox bishops in the way the Pope governs the Roman Catholic Church.

Was the Pope always important?

Yes.

It would be inaccurate to suggest that the early Church treated the Bishop of Rome as simply one bishop among thousands with no particular significance.

Rome had immense prestige.

Its church was associated with the apostles Peter and Paul.

Its bishops were consulted during major disputes.

Rome also held first place among the ancient patriarchal sees.

The real historical debate concerns the extent of that authority.

Catholic interpretation sees the ancient Roman primacy as containing the foundations of later papal jurisdiction.

Orthodox interpretation generally sees it as a primacy exercised within a conciliar structure rather than as universal monarchy.

This remains perhaps the central issue in modern Catholic-Orthodox theological dialogue.

Papal infallibility

Roman Catholic doctrine teaches papal infallibility.

This does not mean Catholics believe the Pope cannot make mistakes.

It does not mean every papal comment is infallible.

The doctrine applies only under specific conditions when the Pope, speaking in his official capacity as supreme teacher of the Church, definitively defines a doctrine concerning faith or morals for the whole Church.

The doctrine was formally defined at the First Vatican Council in 1870.

Eastern Orthodoxy does not accept papal infallibility.

Orthodox theology instead places particular importance on the Church acting through councils and on the reception of conciliar teaching by the whole Church.

The Orthodox Church in America summarises the distinction directly: Orthodoxy does not attribute infallibility to the Pope or any other individual bishop.

Is an Ecumenical Council infallible?

Orthodox Christianity regards the doctrinal teaching of genuine Ecumenical Councils as authoritative.

The process by which a council is recognised as truly ecumenical is nevertheless less centralised than in Catholicism.

Calling a gathering of bishops an ecumenical council does not automatically guarantee its eventual reception as such within Orthodox history.

Orthodox thinking therefore places emphasis on both conciliarity and the reception of the council's teaching by the Church.

Catholicism also recognises Ecumenical Councils but understands them within communion with and confirmation by the Bishop of Rome.

The Filioque

One of the most famous theological differences concerns a single Latin word:

Filioque

It means:

"and the Son."

The original form of the Nicene-Constantinopolitan Creed says that the Holy Spirit proceeds from the Father.

The Western Church gradually began using a version stating that the Holy Spirit proceeds from the Father and the Son.

The Latin term for this addition is Filioque.

The Catholic Church continues to defend the theology expressed by the term.

The Eastern Orthodox Church objects both to the theological implications of particular interpretations and to the historical decision to add words to the Creed without an Ecumenical Council.

The Vatican's own Catechism acknowledges that the phrase was not present in the Creed of Constantinople in 381 and that its later introduction remains a point of disagreement with the Orthodox churches.

What does the Catholic Church mean by Filioque?

Catholic theology does not ordinarily intend the Filioque to create two independent sources of the Holy Spirit.

It teaches that the Spirit proceeds eternally from the Father and the Son as from one principle.

Catholic theology also acknowledges the Father's role as the first origin within the Trinity.

Modern Catholic explanations have increasingly recognised that Greek and Latin theological language historically approached the mystery from somewhat different perspectives.

This has allowed some theologians on both sides to argue that at least part of the historic disagreement may involve differences in terminology and emphasis rather than completely incompatible understandings.

The issue nevertheless remains ecclesiologically important because of how the Creed was altered in the Western Church.

Original sin and ancestral sin

Both Orthodox and Catholic Christianity teach that humanity lives with the consequences of the Fall.

Neither tradition believes that human beings are born into a morally neutral world untouched by Adam and Eve.

The differences concern how this inherited condition is described.

Orthodox writers frequently prefer the term ancestral sin.

They emphasise consequences such as:

• mortality
• corruption
• inclination towards sin
• separation from the fullness of divine life

Orthodox explanations commonly distinguish these inherited consequences from personal guilt for Adam's individual act.

The Orthodox Church in America, for example, states that humanity inherits the consequences of the first sin, especially death, but that Adam and Eve themselves bear the personal guilt of that particular act.

Does Catholicism teach inherited personal guilt?

This subject is frequently oversimplified.

Catholic theology teaches original sin as a fallen condition inherited by humanity.

However, the Catechism of the Catholic Church explicitly distinguishes original sin from a personal fault committed by each newborn individual.

So it is misleading to describe Catholic teaching simply as:

"Every baby is personally guilty of Adam's individual sin."

The deeper difference lies in theological frameworks developed around original sin, grace, baptism and the human condition rather than in the caricature that one side believes babies are personally blameworthy while the other does not.

The Immaculate Conception

The Immaculate Conception is a Roman Catholic dogma concerning Mary.

It does not refer to the conception of Jesus.

It teaches that Mary, from the first moment of her own conception, was preserved from original sin by a singular grace of God in view of the saving work of Christ.

Pope Pius IX formally defined the doctrine in 1854.

Eastern Orthodox Christianity does not accept the dogma in that specific Roman Catholic formulation.

This does not mean Orthodox Christians regard Mary as sinful in the ordinary sense.

Orthodox Christianity venerates Mary extraordinarily highly.

She is called:

• Theotokos
• Mother of God
• Panagia, or All-Holy

Orthodox liturgy repeatedly praises her holiness.

The disagreement is strongly connected with differing understandings of original sin and with Orthodox objections to later unilateral papal dogmatic definitions.

Mary in Orthodox and Catholic Christianity

Both traditions honour Mary far more extensively than most Protestant traditions.

Both affirm:

• the Virgin Birth
• Mary as Mother of God
• her exceptional holiness
• her unique relationship to Christ
• her continuing importance within the communion of saints

Both have numerous Marian prayers, feast days, churches and sacred images.

Differences arise around particular dogmatic formulations.

Roman Catholicism formally defines the Immaculate Conception and the Assumption.

Orthodox Christianity celebrates the Dormition of the Theotokos, commemorating Mary's death and glorification.

There is considerable overlap in belief surrounding Mary's final destiny, but the traditions do not always express that belief in identical dogmatic language.

Clerical marriage

One highly visible difference concerns married priests.

Eastern Orthodox churches may ordain married men to the priesthood.

A man must normally marry before ordination.

An Orthodox priest who is unmarried at the time of ordination normally cannot marry afterwards.

Bishops are ordinarily selected from celibate clergy, traditionally monks or unmarried priests.

Roman Catholic practice is more complicated than the simple statement "Catholic priests cannot marry."

Within the Latin Church, priestly celibacy is the normal discipline.

However, Catholic Eastern Churches often ordain married men according to their own traditions.

There are also limited circumstances in which married former Anglican or Protestant ministers may become Roman Catholic priests.

So the distinction is primarily between Orthodox practice and the normal discipline of the Latin Catholic Church.

Are Orthodox bishops married?

No, ordinarily not.

Orthodox bishops are traditionally chosen from celibate clergy.

This means Orthodoxy maintains both:

• married parish clergy
• celibate episcopal leadership

Monasticism historically supplies many bishops.

Holy Communion

Both Orthodox and Catholic Christianity teach the real presence of Christ in the Eucharist.

Neither tradition normally regards Communion as merely symbolic.

The Catholic Church historically developed the philosophical term transubstantiation to describe how the bread and wine become the Body and Blood of Christ.

Orthodox Christianity also firmly teaches that the Eucharistic gifts truly become Christ's Body and Blood but generally avoids requiring precisely the same scholastic philosophical explanation.

The practical result is that both traditions treat the Eucharist with exceptional reverence.

Why can't Orthodox and Catholics normally receive Communion together?

Because Eucharistic Communion expresses full ecclesial communion.

Orthodox and Catholic churches do not yet possess that full unity.

Therefore, despite extensive shared beliefs about the Eucharist, they normally do not share Communion.

Catholic canon law permits Communion in some restricted circumstances involving Eastern Christians.

Orthodox policies are generally more restrictive and can vary somewhat between jurisdictions.

Visitors should never assume intercommunion is automatically permitted.

Leavened and unleavened bread

Orthodox churches normally use leavened bread for the Eucharist.

The Latin Catholic Church ordinarily uses unleavened bread.

This difference became controversial during medieval East-West disputes but is no longer generally treated as a fundamental theological obstacle.

Eastern Catholic churches often use leavened bread while remaining fully Catholic.

The difference therefore demonstrates how liturgical customs can exist independently from broader ecclesiastical communion.

Baptism and confirmation

Both traditions baptise infants as well as adults.

The sequencing differs.

In Eastern Orthodox Christianity, a newly baptised infant normally receives:

1. Baptism
2. Chrismation
3. Holy Communion

during the same initiation.

Chrismation corresponds broadly to what Western Christianity calls Confirmation.

Roman Catholic children in the Latin tradition often receive Baptism in infancy, First Communion years later and Confirmation according to the local diocesan practice.

Eastern Catholic churches commonly retain patterns closer to Orthodoxy.

Liturgical traditions

Both Catholic and Orthodox Christianity possess highly developed liturgical traditions.

The principal Orthodox Eucharistic service is the Divine Liturgy.

The principal Latin Catholic Eucharistic service is the Mass.

Orthodox churches most commonly celebrate:

• Divine Liturgy of St John Chrysostom
• Divine Liturgy of St Basil the Great
• Liturgy of the Presanctified Gifts during Lent

The Roman Rite is the predominant Latin Catholic liturgy, although Catholicism contains numerous other rites and uses.

Differences visitors may notice include:

• amount of congregational standing
• use of an iconostasis
• style of chant
• frequency of incense
• liturgical language
• altar arrangement
• use of statues
• style of processions
• musical instruments

These differences should not be mistaken automatically for differences in core Christian doctrine.

The iconostasis

A traditional Orthodox church places an iconostasis between the nave and sanctuary.

The screen contains icons and usually includes:

• Royal Doors
• side doors
• Christ
• the Theotokos
• saints
• feast-day imagery

Roman Catholic churches historically developed other ways of distinguishing sanctuary and nave, including altar rails, rood screens and elaborate high altars.

The iconostasis is therefore distinctive but emerged from broader early Christian traditions of sanctuary separation.

Our dedicated article on Orthodox Church Architecture, Icons and the Iconostasis explains its structure and symbolism.

Icons and statues

Orthodox churches are strongly associated with icons.

Roman Catholic churches use both painted sacred images and three-dimensional statues.

Orthodox Christianity traditionally favours icons and generally avoids free-standing devotional statues within church interiors.

The reason is not that three-dimensional art is universally condemned as inherently wrong.

Rather, Orthodox sacred art developed primarily through the iconographic tradition.

Both Catholic and Orthodox Christianity distinguish veneration from worship.

Worship is given to God alone.

Sacred images and saints may be honoured.

This shared principle separates both traditions from Protestant movements that historically rejected or greatly reduced the use of sacred images.

Saints

Both traditions venerate saints.

Many saints from before the East-West separation are honoured by both churches.

Examples include:

• St Peter
• St Paul
• St Nicholas
• St John Chrysostom
• St Basil the Great
• St Augustine
• St Ambrose
• St Benedict
• St Gregory the Great

After the division, each tradition developed saints not formally recognised by the other.

Orthodox saints include figures such as:

• St Seraphim of Sarov
• St Silouan the Athonite
• St Paisios the Athonite

Catholic saints include:

• St Francis of Assisi
• St Teresa of Ávila
• St Thérèse of Lisieux

The existence of separate canonisation processes reflects the lack of full ecclesiastical communion.

Canonisation

The Catholic Church has a highly centralised canonisation process involving investigation and ultimately papal declaration.

Orthodox canonisation is more decentralised.

A local autocephalous church may formally glorify a saint.

Recognition can subsequently spread throughout wider Orthodoxy.

Both traditions understand canonisation not as making someone a saint but as recognising holiness already present.

Confession

Both Orthodox and Catholic Christians practise sacramental confession.

In Roman Catholic practice, the penitent may confess within a traditional confessional or another suitable setting.

Orthodox confession commonly takes place before an icon of Christ or the Gospel Book, with the priest standing beside the person confessing.

In both traditions:

• sins are confessed
• repentance is required
• a priest provides pastoral guidance
• absolution is given

The precise wording, setting and discipline differ.

For more on the Orthodox practice, see Orthodox Prayer and Worship: Traditions, Fasting and Devotion.

Original sin and baptism

Both traditions baptise infants partly because baptism is understood as entry into the life of Christ and the Church rather than simply a public declaration made after reaching intellectual maturity.

Catholic theology speaks of baptism removing original sin.

Orthodox Christianity likewise understands baptism as participation in Christ's death and resurrection and liberation from the fallen condition associated with Adam.

The theological vocabulary differs, but both traditions reject the idea that baptism is merely symbolic.

Purgatory

Roman Catholic teaching includes the doctrine of purgatory, describing purification after death for those destined for salvation but still requiring purification.

Eastern Orthodoxy does not accept the Roman Catholic dogmatic formulation of purgatory.

Orthodox Christianity does, however, pray for the dead.

This is important.

Rejecting the Catholic doctrine of purgatory does not mean Orthodoxy teaches that prayer for the departed is pointless.

Orthodox Christians regularly commemorate the dead during liturgy and memorial services.

The precise theological understanding of the intermediate state is generally expressed less systematically in Orthodoxy than in Western scholastic theology.

Divorce and remarriage

The traditions also differ in their pastoral treatment of failed marriages.

Roman Catholicism teaches that a valid sacramental marriage cannot be dissolved.

An ecclesiastical tribunal may declare that a valid marriage was never actually constituted, through the process commonly called annulment.

Eastern Orthodox churches also uphold marriage as lifelong.

However, under particular circumstances, many Orthodox jurisdictions permit a second and sometimes third marriage through a penitential process after divorce.

The difference reflects distinct canonical and pastoral developments.

Calendar differences

Orthodox and Catholic feast dates can differ because different calendars are used.

The Roman Catholic Church follows the Gregorian calendar.

Orthodox churches use different systems.

Some continue to use the Julian calendar for fixed feasts.

Others use the Revised Julian calendar, which currently corresponds with the Gregorian calendar for fixed feast dates.

This explains why some Orthodox Christians celebrate Christmas on 25 December while others currently celebrate it on 7 January according to the civil Gregorian calendar.

Why is Orthodox Easter often on a different date?

The calculation of Pascha, or Easter, involves both calendar and traditional computus rules.

Catholics and most Western Christians use the Gregorian calendar calculations.

Orthodox churches traditionally calculate Pascha using the Julian calendar framework.

The dates can sometimes coincide and sometimes differ by several weeks.

The theological feast is the same: the resurrection of Christ.

The difference concerns calendar calculation.

Fasting

Both Catholic and Orthodox Christianity preserve traditions of fasting.

Orthodox fasting is generally more extensive in traditional practice.

Orthodox Christians may observe:

• Great Lent
• Nativity Fast
• Dormition Fast
• Apostles' Fast
• most Wednesdays
• most Fridays
• individual fast days

Roman Catholic discipline currently requires fasting and abstinence on a smaller number of mandatory days, although individual Catholics may undertake additional fasting.

Historically, Western Christian fasting was considerably more extensive than modern Catholic minimum requirements.

See our full guide to Orthodox prayer and fasting traditions.

The Sign of the Cross

Both traditions make the Sign of the Cross.

Eastern Orthodox Christians traditionally move:

forehead → torso → right shoulder → left shoulder

Latin Catholics ordinarily move:

forehead → torso → left shoulder → right shoulder

Orthodox Christians also commonly join three fingers to represent the Trinity.

These differences developed through historic custom rather than representing fundamentally different beliefs about the Cross.

Sacred Heart and other Western devotions

Roman Catholic spirituality developed a number of devotions that are not ordinarily found within Eastern Orthodoxy.

Examples include:

• Sacred Heart of Jesus
• Divine Mercy chaplet
• Stations of the Cross
• Eucharistic adoration in Western forms
• particular forms of the Rosary

Orthodox Christianity developed its own distinctive devotional forms, including:

• Jesus Prayer
• prayer rope
• Akathist hymns
• Paraklesis
• canons
• extensive icon devotion

These illustrate how the two traditions developed different spiritual cultures even while sharing basic sacramental Christianity.

The Rosary and the Orthodox prayer rope

The Roman Catholic Rosary combines repeated vocal prayers with meditation on events in the lives of Christ and Mary.

The Orthodox prayer rope is commonly used for repeated invocation of the Jesus Prayer.

They can look superficially similar because both use physical counters.

But their devotional structure is different.

It is therefore inaccurate simply to call the prayer rope an "Orthodox rosary".

Monasticism

Both traditions maintain monastic communities.

Eastern Orthodoxy does not generally divide monasteries into numerous distinct religious orders in the Western sense.

Orthodox monasteries share the wider monastic inheritance associated with figures such as St Basil and the desert fathers.

Roman Catholicism developed major religious orders including:

• Benedictines
• Cistercians
• Franciscans
• Dominicans
• Carmelites
• Jesuits

These orders developed distinctive rules, missions and spiritual emphases.

Orthodox monasticism has its own regional traditions but is organisationally less divided into separate orders.

What do Orthodox and Catholics believe about salvation?

Both traditions teach salvation through Jesus Christ and reject the idea that human beings can save themselves independently of divine grace.

Both connect salvation with:

• faith
• grace
• baptism
• repentance
• Eucharist
• Christian life
• love of God and neighbour

Orthodox theology often places particular emphasis on theosis, participation in divine life.

Catholic theology also possesses strong traditions of sanctification, union with God and divinisation, although Western theological language historically developed additional legal and scholastic categories.

Popular debates sometimes exaggerate this difference.

What is theosis?

Theosis is the Orthodox term for humanity's transformation through communion with God.

It does not mean humans become God by nature.

Rather, human beings participate in God's grace and are transformed into what they were created to become.

The concept is deeply rooted in early Christian theology and is not entirely foreign to Catholic thought.

Catholic theology also speaks of participation in divine nature and divinisation.

The difference is partly one of theological emphasis and vocabulary.

Scripture and Tradition

Both Eastern Orthodox and Roman Catholic Christianity reject the Protestant principle of Scripture alone when understood as separating biblical authority from the historic Church.

Both affirm:

• Holy Scripture
• apostolic tradition
• early Church Fathers
• councils
• liturgical tradition

The Catholic Church additionally defines the teaching authority of the Church through the Magisterium, exercised by bishops in communion with the Pope.

Orthodoxy emphasises Holy Tradition as the life of the Church preserved through Scripture, councils, worship and episcopal continuity.

Both traditions therefore differ substantially from Protestant models that place final interpretive authority in Scripture considered independently of a binding church teaching office.

The biblical canon

Orthodox and Catholic Bibles contain more Old Testament books than most Protestant Bibles.

Catholicism includes the books commonly called Deuterocanonical.

Orthodox Christianity also receives a longer Old Testament canon rooted in the Greek Septuagint tradition.

Exact Orthodox canonical lists can contain some variations compared with the Roman Catholic canon.

The Orthodox Church in America notes that books such as Tobit, Judith, Wisdom, Sirach and Maccabees form part of the Orthodox Old Testament tradition.

Areas where Orthodox and Catholics agree

The amount of agreement is substantial.

Both believe in:

• one God
• the Trinity
• divinity of Christ
• humanity of Christ
• Virgin Birth
• Crucifixion
• bodily Resurrection
• Ascension
• Holy Spirit
• apostolic succession
• bishops
• priests
• deacons
• Baptism
• Eucharist
• Confession
• sacramental marriage
• saints
• prayer for the dead
• veneration of Mary
• religious images
• monasticism
• resurrection of the dead
• eternal life

Both recognise the theological importance of the early Church Fathers and ancient councils.

Both also preserve liturgical Christianity rather than organising worship primarily around preaching.

The extent of this shared inheritance explains why modern ecumenical dialogue has focused particularly on questions of church authority rather than attempting to construct a common Christianity from scratch.

Do Orthodox Christians regard Catholics as Christian?

Yes, in the ordinary sense that Catholicism is recognised as a Christian tradition centred on belief in Christ and the Trinity.

Orthodox approaches to the precise ecclesiological status of Christians outside canonical Orthodoxy can vary among theologians and jurisdictions.

Some use stricter language than others.

It is therefore safer not to pretend that one universal Orthodox formula exists for every aspect of how Catholic sacramental life is described.

Does the Catholic Church recognise Orthodox sacraments?

The Roman Catholic Church recognises Orthodox apostolic succession and sacraments.

This is one reason Catholic treatment of Eastern Orthodox Christianity differs significantly from its approach to many Protestant communities.

Catholic teaching regards Orthodox Eucharist and priesthood as valid despite the absence of full communion.

Why aren't the churches reunited?

The principal unresolved issue concerns authority within the universal Church, particularly the role of the Bishop of Rome.

Other theological and canonical questions remain important.

Centuries of separate institutional development also create practical difficulties.

A reunion would have to address:

• papal primacy
• universal jurisdiction
• synodality
• historical councils
• later Catholic dogmas
• canonical territories
• pastoral practice

A simple declaration that the churches have much in common cannot resolve these issues by itself.

The 1965 removal of the excommunications

An important breakthrough occurred on 7 December 1965.

Pope Paul VI and Ecumenical Patriarch Athenagoras I issued a joint declaration concerning the mutual condemnations associated with 1054.

They expressed regret for the actions and language surrounding those events and removed the historic sentences of excommunication from memory.

The declaration explicitly acknowledged that the events had led to consequences far beyond what their original authors intended.

It did not restore sacramental communion.

Instead, it opened a new period of formal reconciliation and theological dialogue.

Modern Catholic-Orthodox dialogue

Formal theological dialogue between the Catholic and Orthodox churches has continued for decades.

The Joint International Commission for Theological Dialogue between the Roman Catholic Church and the Orthodox Church was established to examine areas of agreement and unresolved disagreement.

A central subject has increasingly become the relationship between:

• primacy
• synodality
• authority
• the Bishop of Rome
• local churches

The theological question is not simply whether primacy should exist.

Both traditions recognise forms of primacy.

The harder question is what authority the first bishop should possess and how that authority should operate within a synodal Church.

Dialogue remains active today.

Why the first millennium matters to modern dialogue

Catholic and Orthodox theologians frequently return to the first millennium because the churches were then in communion.

The central question becomes:

How did Roman primacy function when East and West still belonged to one sacramental communion?

Catholic theologians look for evidence supporting a universal Petrine ministry.

Orthodox theologians emphasise the synodal and regional structures that limited unilateral authority.

Studying the first millennium therefore provides a potential historical framework for imagining restored communion without simply imposing the modern administrative structure of one church upon the other.

Can Orthodox and Catholic churches reunite?

No timetable exists.

Modern relations are considerably better than they were for much of the second millennium.

Popes and Ecumenical Patriarchs meet regularly.

Formal theological dialogue continues.

The mutual excommunications associated with 1054 have been removed from memory.

The churches cooperate on numerous social and humanitarian issues.

Yet substantial theological and ecclesiological disagreements remain.

Full communion would require far more than diplomatic goodwill.

It would involve agreement about the structure and authority of the universal Church.

Orthodox and Catholic churches in Britain

Britain provides many opportunities to encounter both traditions.

Roman Catholic churches are found throughout the country and form one of Britain's largest Christian communities.

Eastern Orthodox communities have also grown significantly through Greek, Romanian, Ukrainian, Serbian, Russian, Bulgarian, Georgian and Middle Eastern migration.

In some cities, Orthodox and Catholic churches stand only a short distance apart while embodying visibly different Christian traditions.

Visitors interested in exploring that heritage can continue with:

• Best Orthodox Churches in the UK
• Best Cathedrals in the UK
• Best Abbeys and Monastery Ruins in the UK

Frequently asked questions

Continue exploring Religious Heritage

Orthodox Christianity: History, Beliefs and Traditions Explained
A comprehensive introduction to Eastern Orthodox history, theology, worship and church structure.

Orthodox Prayer and Worship: Traditions, Fasting and Devotion
Explore the Jesus Prayer, prayer ropes, fasting, confession and devotional traditions.

Orthodox Church Architecture, Icons and the Iconostasis
Understand Royal Doors, icons, the sanctuary and Orthodox sacred architecture.

A Brief History of Ukrainian Orthodox Christianity
Follow the history of Ukrainian Christianity from Kyivan Rus' to modern autocephaly.

The Tree of Life in Christianity
Explore the biblical and Christian symbolism of the Tree of Life from Genesis to Revelation.

Best Orthodox Churches in the UK
Discover notable Orthodox churches and communities across Britain.

Best Cathedrals in the UK
Explore Britain's cathedral architecture and religious history.

Final thoughts

Eastern Orthodox and Roman Catholic Christianity are simultaneously close relatives and separate ecclesiastical traditions.

Their shared inheritance is enormous.

They confess the same Trinity, proclaim the divinity and humanity of Christ, celebrate sacramental worship, maintain episcopal succession, honour saints and Mary, practise monasticism and trace their roots to the Church of the first Christian centuries.

The division lies less in the basic question of whether Christianity should have bishops, sacraments, tradition or liturgical worship than in how authority and particular doctrines developed after the first millennium.

The authority of the Bishop of Rome remains the central institutional disagreement.

The Filioque illustrates differences in theological language and church authority.

Original sin and the Immaculate Conception reveal different theological frameworks inherited by East and West.

Married clergy, liturgical practices, calendars and sacred art make the distinction visible at parish level.

Modern dialogue has nevertheless transformed the relationship.

The mutual condemnations associated with 1054 were removed from memory in 1965, formal theological dialogue continues, and both churches increasingly acknowledge how much Christian inheritance they still share.

That does not mean reunion is imminent.

It does mean the Orthodox-Catholic relationship is better understood as a long-standing separation within historic Christianity than as a contest between completely unrelated forms of faith.