St. Augustine of Hippo

Holy Father (How God saved a soul from the Greek Schism)
I Left Eastern Orthodoxy for the Church Led by Pope Francis, and I Don’t Regret It
The Filioque: Again and Again on Bended Knee
Palamas and Aquinas: the Metaphysical Wordwebs of the Athenians
Ten Lessons for the Chalcedonians from their rapprochement with the Miaphysites
The Council of Florence: No Scholarly Consensus?
The Greek Schism is a Result of Rejecting the Latin Fathers
The Greek Schism is a Result of Rejecting the Latin Fathers Pt. 2
The Three Interpolations in the Latin Nicene Creed

Understanding the Orthodox Churches

The dominant church is Russia, which outnumbers all the other Orthodox churches combined. Thus the main form of Orthodoxy that we get in English is from Russia. Two main groups fled the Soviets. One group went to Paris and founded a school, and then in the USA (St. Vladimir’s) and this is the Parisian school of thought. They are Meyendorff, Schmemann, Gillet, Hopko, and especially Florovsky, their greatest scholar. They learned Latin and studied the Latin saints and Fathers and were able to understand them well. This is why Florovsky said, for instance, that Augustine is “the greatest Father of the Church universal.”

The other main group took refuge in Serbia, known for its nationalism and anti-Roman bias, owing to its Roman Empire aspirations. This group was also influenced by “St.” Popovic there, and this group was dominated by ROCOR (Russian Orthodox Church Outside Russia) who excommunicated all other Orthodox churches (save Jerusalem) and were schismatics to the other Orthodox churches until they reconciled with Moscow around 2007. This group did not take the time to learn Latin and so they don’t understand Roman Catholicism very much at all.

So the two dominant camps in English are the Ruso-Parisian school, and the Serbo-ROCOR school. The former understands Roman Catholicism to a large degree and has published good scholarship interacting with the Roman Catholic dialogue.

The later group dominates the website http://orthodoxinfo.com, which appears as some kind of official Orthodox website. But ROCOR was schismatic from most Orthodox churches for nearly 100 years. Nevertheless http://Orthodoxinfo.com still asserts their version of Orthodoxy is the only true one. The most famous writer of the later Serbian school is Seraphim Rose, whom many of that camp venerate as a saint.

The Parisian school is the mainstream in English, taught in many Orthodox seminaries in western lands, whereas the Serbian-ROCOR school is a fringe group in regards to the whole Orthodox churches.

There is a more fringe group than them however. That is the thesis of Joseph P. Farrell, who asserted that Augustine’s metaphysical “errors” caused the downfall of all of western civilization. This assertion is so extreme that not even Mark of Ephesus would countenance such nonsense, since he read Augustine with reverence as the Ecumenical Councils affirmed him as a Father. Joseph Farrell later became an Old Calendarist schismatic (which is even more extreme than the ROCOR school) and then turned to heretical Marcianism and wrote a book about how the God of the Old Testament was evil. This fringe group led by Farrell is the one that popular YouTuber Jay Dyer subscribes to (he should be ignored as not a reliable source of Orthodox information).

Then we have the other main church besides the Russians: the Greeks. The Greeks and Russians have been in an informal schism since the 1500s because they cannot agree on what ecclesiastical governance is. Their ecclesiologies are different, and they have different theologies and practices especially in sacramental theology. They essentially form two Orthodox groups of Churches, with most of the rest following one or the other more or less.

This informal schism has broken out into proxy schism with Bulgaria (1870-1945) and Estonia (1996) and now formal separation since 2018.

Further, we can then discuss the Antiochian Orthodox, who famously opposed the Greek schismatics in 1054. One such Antiochian has published a book arguing that the Great Schism was most of all an invention of the Muhammadans, who imposed it for political purposes after they drove out or killed the Greek Catholics from Constantinople in 1453 (Lina Nehme, Muhammad II Imposes the Orthodox Schism). Their former patriarch Ignatios IV has publicly stated that “the disagreement between Orthodox and Catholics is not dogmatic…we are capable of uniting with Rome” (June 1983). But there are so few Antiochians that their influence is minimal, and the Antiochian Church in the USA is dominated by Greek and Russian influence to a large extent. They don’t have their own seminary.

Finally, we can discuss the Non-Chalcedonians (“Oriental”) and the Assyrians (“Nestorian”), who are Orthodox churches not in communion with either the Greek churches or the Russian churches. They are the fewest in number and have the least influence, but their dialogue with the rest of the Orthodox has opened up all the Orthodox churches to further dogmatic and ecclesiological questions.

The critical point about these two other Orthodox communions is that they reject the papacy on the same basis that the rest of Eastern Orthodoxy does, yet disagree fundamentally on how many ecumenical councils are valid. In other words, if you want to convert to Orthodoxy, you need to further justify why you are not Oriental Orthodox or Assyrian Orthodox, because these other two eastern communions also confess the Concliarist model of ecclesiology but are divided from the rest of Eastern Orthodoxy. Some argue the Assyrian church was the dominant church in the world until 1300 (Jenkins, The Lost History of Christianity).

In short, the Orthodox churches are divided irrevocably and anyone who tells you otherwise does not understand the situation. So if you are going to talk to Orthodox bishops, priests and scholars, you’re going to get very different doctrines and views depending on who you talk to. So the first question for you is which camp do you want to favor? We’ve got camps in Catholicism too, but it’s a bit less complicated because we possess a living Magisterium which adjudicates questions and brings about unity on things like sacramental theology. Because of the division among the Orthodox, they do not even agree on who should be baptized and who should not be baptized when converting. See this essay for more: I Left Eastern Orthodoxy for the Church Led by Pope Francis, and I Don’t Regret It