Assyrian Church of the East First Church?


Hello everyone. I was talking to my friend who is a part of the Assyrian Church of the East said it was historically proven that the ACotE was founded by the apostles themselves. I asked if they are in accordance with the Pope and he said no. So is it true they are the first church, before Catholicism, and would they be considered Protestant or more a form of Oxydoxy?


They are an Apostolic Church which is not in communion with Rome. The Catholic Church recognizes that the Assyrian Church of the East has Apostolic succession and a valid Eucharist.

They are definitely not Protestant. I believe that the Assyrian Church of the East broke communion with Rome and the rest of the East after The Council of Chalcedon. Their Catholic counter part is the Chaldean Catholic Church



Neither. They are Nestorians (see CCC 466)–they only accept the first two ecumenical Councils.

But to address the issue raised, we need to look at this question from two perspectives: that of the universal/catholic Church and that of particular churches (a particular church being a bishop and his flock celebrating the Eucharist). Not all particular churches belong to the one catholic/universal Church professed in the Creed.

Christ founded one Church–there is and always will be only one Church of Christ. At various times, certain communions (e.g. Assyrian Church of the East, Greek Orthodox, etc.), which were groups of particular churches, broke communion with the universal Church (which is the Catholic Church alone). Many of those particular churches had ancient origins, even being founded directly by an Apostle in certain cases. But since there is only one Church, all of the resulting separated communions cannot each be it.

In that sense, new societies/communions came into being at those times that are not the one Church professed in the Creed, even though they are made up of particular churches of ancient origin that previously were part the universal Church founded by Christ.

So yes, they have an ancient origin, but when they broke the bonds of faith with the universal Church, they departed from it. So they are not the same society as the original church.


The Assyrian Church of the east isn’t Nestorian. That was settled with the common declaration made a few decades ago between the Catholic Church and the ACoE.


The Catholic Church and the Assyrian Church were one Church for about 400 years, but disagreement with the Council of Ephesus in 431 AD led to the Assyrian Church breaking communion with Rome.

There are also the Oriental Orthodox, who broke communion when they did not accept the Council of Chalcedon in 451 AD, and the Eastern Orthodox who broke communion with Rome (and vice versa) due to the events of the Great Schism in the 11th century. There are some particular Churches from these that have since entered back into communion with Rome, but not all. This is all broad strokes, and it gets more nuanced than that.

The Roman Catholic Church, Eastern Orthodox, Oriental Orthodox, and Assyrian Church all have legitimate claims to being apostolic Churches, that is, continuations of particular Churches founded by the Apostles. This doesn’t mean the Catholic Church considers them all to be in 100% right order, but this is different than the branches of Protestant and Reconstructionist movements, which by Catholic teaching have lost their Apostolic succession and have different understandings of the Church, sacraments, etc…

This graphic may help.



From what I understand from the graph, the Assyrian Church and Oriental Orthodox are in union with the catholic church, but I though this was not the case.


The above graphic is simplified.


The graph means that a branch of the Assyrian church came to be in union with the Catholic church, eastern rite, and that likewise branches of the Oriental Orthodox church came to be in union with the Catholic church, in the eastern rites. But the rest of the Assyrian church remained separate, and the rest of the Oriental Orthodox churches remained separate, not in union with the Catholic church, not in union with the Catholic pope.


The most balanced one could say is that the Catholic Church and Assyrian Church split at once. How could Assyrian church predate Catholicism, when most Christians remained Catholic after the split? Additionally, the Assyrian church today is very small.


Also, the Chaldean Catholic Church — the part of the Assyrian church that united with Rome (Catholic Church) — consists of more Christians than the modern Assyrian Church of the East.


According to tradition, they were founded by St Thomas. They could be said to be the oldest Church in the sense that they have been developing in a degree of isolation from other Christian Churches for the longest period of time. You could say that they are the oldest Church to have preserved an identity distinct from that of other Churches.

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