There seems to be something of a divide within Eastern Orthodoxy today on one of the most fundamental issues of the faith- the identity of the one God. Many Eastern Orthodox theologians and laypeople believe that the one God is tri-personal or triune, comprised of Father, Son, and Holy Spirit together in a single being. Others, however, following an older tradition, have embraced a triadology that is fundamentally unitarian, believing in the one God as only a single person, the God and Father of the Lord Jesus; in their view, the Son and Holy Spirit share a generic nature with this one God, but are numerically distinct from Him. The Eastern Orthodox call this idea that the one God is only one person, the Father, ‘the Monarchy of the Father’ and don’t like the ‘unitarian’ label- but disputes over wording aside, it’s the same idea.
The history behind this divide is a long one, stemming ultimately from what some Eastern Orthodox have called a “patristic renaissance” in the last few centuries, in which many Eastern Orthodox have sought to return to their roots by going back to the Greek Church fathers for instruction. Prior to this the Eastern Orthodox Churches experienced several centuries of oppression by Muslim rulers which lead many EO clerics to get their training in western seminaries, often giving their theology a bit more of a western tint. The ‘patristic renaissance’ ostensibly serves to correct this some, and to reground Eastern Orthodox thinking back in their own unique heritage. The result has been that some have rediscovered ‘the Monarchy of the Father’ among those ancient writings, and now there is a significant push to bring this doctrine back into the spotlight in Eastern Orthodox triadology.
Trinitarianism (the belief in a triune God) has been deemed by the proponents of the Monarchy of the Father as an invention of the Latin church, the result of serious misunderstanding of orthodox and creedal triadology, while in their view, the Greek churches faithfully upheld Monarchian Triadology at least into the time of Photius I in the ninth century. In other words, they see trinitarianism (the belief that the one God is triune) as a uniquely western error, developing in the late fourth century, that was not accepted by the Eastern churches generally. Others such as myself, and more notably, Dr. Dale Tuggy, have argued that while the doctrine of a triune God is indeed a late doctrinal development coming at the end of the fourth century, it is not a uniquely western error. Dr. Tuggy argues persuasively in his most recent paper that from the end of the fourth century the doctrine of a triune God had proponents in the East, among the most influential bishops of the time, such as Gregory Nazianzen. For political reasons this doctrine was not expressly affirmed at the council of 1 Constantinople in 381, but can be found in several eastern sources well before Photius I, as Dr. Tuggy outlines in his paper.
I recently became aware of an additional source showing this, and wanted to share it here. There was an Eastern bishop active in the late sixth and early seventh century named Sophronius, the Patriarch of Jerusalem, who wrote an encyclical letter detailing, among other things, what he regards as the orthodox understanding of the Trinity. In it, he speaks clearly of the one God as the entire Trinity- that is, a triune or tri-personal God:
“Nor as the one God is a Trinity and is recognized and proclaimed as three hypostases and worshipped as three persons, Father, and Son, and Holy Spirit, is he said to be contracted or compounded or confused, that is, by coalescing himself into one hypostasis and combining [himself] into one person that cannot be numbered.” (Sophronius of Jerusalem and Seventh-Century Heresy, p. 77)
Notice that the one God is directly stated to be a trinity of three persons, that is, a single ‘tri-personal God’. The one God that is described as a trinity here is also a single “he” and “himself”, further solidifying that the one God here is presented as an individual, not merely a generic nature shared by three individuals. Put in more technical terms, the unity of being ascribed to the Trinity here is an individual/numerical consubstantiality, not a generic consubstantiality.
“The Arians’ impiety divides the one God into unequal gods and partitions the one Godhead into dissimilar godheads, and separates the one lordship into three heterogeneous lordships.” (ibid, p. 77)
This criticism of Arianism only makes sense in a context where the one God is regarded as the entire Trinity together, rather than the person of the Father in particular. The Arians are said to divide the one God into unequal parts- that is, they make the three persons of the triad unequal and different. That means that it’s the triad, all three persons together, that are being spoken of as singly being the one God here.
“As, therefore, we have been taught to think of one God, so too we have received the tradition of confessing one Godhead; and just as we have learned to worship three hypostases, so too have we been instructed to glorify three persons, not acknowledging the one God apart from the three persons, nor understanding the three consubstantial persons in the Trinity -that is, Father, Son, Holy Spirit- as being distinct from the one God.” (ibid, p. 79)
At first this almost makes it sound like there’s a difference drawn between the one God and the one Godhead, but it rather seems to be the case that these are being equated- the belief in one God is articulated as belief in a single Godhead that exists as three persons. This is confirmed when we see him speak of hypostases and persons in a similarly confusing way, almost as if he is drawing a distinction between them- but obviously he is not. The one God for him just is the one Godhead that exists in three persons, and the three hypostases just are the three persons. The declaration that all three persons of the Trinity -Father, Son, and Spirit- cannot be understood as distinct from the one God is utterly incompatible with the Monarchy of the Father, in which the Son and Spirit are as distinct from the one God as they are from the Father, because in that view, the Father just is the one God.
The fact that one of the Eastern Orthodox Patriarchs in the early sixth century articulates the doctrine of the Trinity this way is a death-blow for the view that the doctrine of a triune God was a purely western mistake, not embraced by the Eastern churches. A Greek Patriarch in Jerusalem speaks the same way Augustine and the Roman Popes speak in the West. But, there’s more- this letter was also accepted by Pope Agathos I, in an official capacity:
“We have also examined the synodal letter of Sophronius of holy memory, some time Patriarch of the Holy City of Christ our God, Jerusalem, and have found it in accordance with the true faith and with the Apostolic teachings, and with those of the holy approved Fathers. Therefore we have received it as orthodox and as salutary to the holy Catholic and Apostolic Church, and have decreed that it is right that his name be inserted in the diptychs of the Holy Churches.”
That’s important because that letter by Pope Agathos I and his rulings in it -including the official reception and approbation of Sophrinius’ letter- was adopted by the so-called 6th ecumenical council, the 3rd council of Constantinople, later in the seventh century (see the acts of that council, including that letter, here).
This means that Patriarch Sophronius’ statements about one God who is three persons (a ‘triune God’), quoted above, end up not only expressing his own opinion, but are also part of the official canonical teaching of an ecumenical council, the rulings of which are considered binding upon the Eastern Orthodox churches. This lays waste to the notion that the doctrine of a tri-personal God was limited to the Latin church while the Greek churches kept themselves clean from it; it’s on the books for both, by way of the ruling of an ecumenical council.
This has lots of implications for the Eastern Orthodox church. It means that they did (like the Roman church) experience a development of doctrine in which they changed from a belief in the one God as being only a single person, the Father, to believing that the one God is a ‘triune God’ consisting of Father, Son, and Spirit together. Further it demonstrates that their conception of consubstantiality developed from a view of generic consubstantiality (a shared nature among three individuals) to an individual consubstantiality (where Father, Son, and Spirit are just the same individual). That doesn’t look very good for the claim that their views have not changed over time, nor does it comport well with the supposed infallibility of these “ecumenical” councils, since (as many modern EO like to point out) the earliest “ecumenical” council, Nicea, did not affirm this doctrine, but rather affirms the Monarchy of the Father/unitarianism. This reveals a serious conflict within Eastern Orthodox tradition itself, as the teachings of their bishops and councils disagree with each other.