Compare
Eastern Catholic ChurchesandGreek Orthodox Church
At a glance
- Common groundIn full: Common ground
- Common inheritanceA shared first millennium: the 'full communion of faith, fraternal accord and sacramental life' that both churches recall from before their estrangement, including the ecumenical councils, the Nicene Creed and bishops in apostolic succession.
2 sources
- Joint Catholic–Orthodox Declaration of His Holiness Pope Paul VI and the Ecumenical Patriarch Athenagoras I, ¶5Source verified
- The Filioque: A Church-Dividing Issue? An Agreed StatementSource verified
Provisional: broadly supported, but awaiting fuller checking.
- GodOne God in three persons: Father, Son and Holy Spirit
- ChristChrist is fully divine and fully human; Two natures united in one person, as defined at Chalcedon (451)
- Church and ministryBishops in historic apostolic succession
- Common inheritanceA shared first millennium: the 'full communion of faith, fraternal accord and sacramental life' that both churches recall from before their estrangement, including the ecumenical councils, the Nicene Creed and bishops in apostolic succession.
- Key differencesIn full: Key differences
- Scripture and authorityEastern Catholic ChurchesScripture and Tradition, interpreted by the bishops in communion with the popeGreek Orthodox ChurchScripture read within Holy Tradition, the councils and the Fathers
- Church and ministryEastern Catholic ChurchesBishops in communion with the pope, who holds universal jurisdictionGreek Orthodox ChurchBishops governing in synods; self-governing churches without a universal head
- Creeds and councilsBothThe first three ecumenical councils (325, 381, 431); The fourth to seventh councils (451 to 787)Eastern Catholic Churches alsoLater general councils of the Western Church, including Trent and the Vatican councils
- How their histories connectIn full: How their histories connect
- Lines parted · Various, 16th–20th centuries · A gradual process · Through the wider familyUnions with Rome (ecclesial union)Read the account in Eastern Catholic Churches
- Line of descentGreek Orthodox Church became self-governing from the Ecumenical Patriarchate of Constantinople (1833).
- Connected today?In full: their relationship today
Parts of one churchas of September 2026
Part of the Catholic Church, which comprises 24 churches sui iuris: the Latin Church and 23 Eastern churches.
Source
Composed from each tradition’s sourced records. Where a topic is not yet recorded for one side, the Atlas says so rather than guess.
Structured comparison. Composed from each tradition’s sourced position records. No research has yet been written for this particular pair, so the Atlas shows only what those records establish.
Where they differ
Creeds and councils
Councils received
- Eastern Catholic Churches
- The first three ecumenical councils (325, 381, 431); The fourth to seventh councils (451 to 787); Later general councils of the Western Church, including Trent and the Vatican councils
- Greek Orthodox Church
- The first three ecumenical councils (325, 381, 431); The fourth to seventh councils (451 to 787)
Scripture and authority
Sources of authority
- Eastern Catholic Churches
- Scripture and Tradition, interpreted by the bishops in communion with the pope
- Greek Orthodox Church
- Scripture read within Holy Tradition, the councils and the Fathers
Church and ministry
Church government
- Eastern Catholic Churches
- Bishops in communion with the pope, who holds universal jurisdiction
- Greek Orthodox Church
- Bishops governing in synods; self-governing churches without a universal head
Not yet comparable (2)
No sourced position is recorded for one side, so the Atlas does not say whether they agree:
- Creeds and councils (the filioque): not recorded for Eastern Catholic Churches
- Salvation and grace (characteristic emphasis): not recorded for Eastern Catholic Churches
How their histories relate
Ecclesial union · Various, 16th–20th centuriesA gradual processWider family
Part of one church enters communion with another while keeping its own liturgy, hierarchy and law.
The 23 Eastern Catholic churches did not form through one event. Several came from unions of parts of Eastern churches with Rome (the Union of Brest, 1596; Uzhhorod, 1646; the Melkite patriarchate, 1724; the Syro-Malankara Church, 1930); the Maronites and Italo-Albanians describe themselves as never having broken communion.Read in Eastern Catholic Churches historySource
Their relationship today
Parts of one churchas of September 2026
Source
This record concerns the wider family to which one or both belong.
Based on Unions with Rome
Developments towards reconciliation
No documented agreement or formal dialogue between these traditions is recorded in the Atlas.
Explore further
Eastern Catholic Churches
All citations link to the Atlas’s single source register.