Against Generic Co-essentiality

Having dealt a lot with the heretical doctrine of numerical or individual coessentiality in past articles, I want to address in this post the doctrine of generic or natural co-essentiality. This doctrine differs enormously from the former; while the former teaches that the Father and Son are the same individual substance, that is, the same individual being or person, the latter which we shall address here pertains to the notion that the Father and Son, as two genuinely distinct individual beings, or persons, share one and the same generic nature.

This idea was the view which prevailed, thanks to Emperor Theodosius, within the Roman Empire at the close of the fourth century, becoming the official dogma of the Eastern churches under Byzantine rule (the Western churches only very briefly, if at all, held to this view, instead embracing the Sabellian doctrine of numerical coessentiality). Such notable Homoousians as Athanasius and Basil the Great held and promoted this doctrine of generic coessentiality, which to this day, despite modalistic influence, has a continued following in Eastern Christianity and among some Protestants.

The idea of generic co-essentiality is that of a shared nature, genus, or species; Basil summed it up as “The distinction between οὐσία [essence] and ὑπόστασις [person] is the same as that between the general and the particular ; as, for instance, between the animal and the particular man.” (Letter 236); Athanasius said “Even this is sufficient to dissuade you from blaming those who have said that the Son was coessential with the Father, and yet let us examine the very term ‘Coessential,’ in itself, by way of seeing whether we ought to use it at all, and whether it be a proper term, and is suitable to apply to the Son. For you know yourselves, and no one can dispute it, that Like is not predicated of essence, but of habits, and qualities; for in the case of essences we speak, not of likeness, but of identity. Man, for instance, is said to be like man, not in essence, but according to habit and character; for in essence men are of one nature. And again, man is not said to be unlike dog, but to be of different nature. Accordingly while the former [men] are of one nature and coessential, the latter are different in both.”

The idea, then, is of a nature shared among multiple distinct persons or individual beings (hypostases); just as three men share a common human nature, a set of communicable ontological properties possessed by all men, which define a given being as “human”, so the persons of the Trinity, these fathers taught, share a common nature which makes them ontologically identical. The Son in comparison to the Father is often summed up, in this view, to be ‘everything that the Father is, except that He is begotten, not unbegotten’. He is then equal to and identical to the Father in all attributes, except the causal relation of having been begotten by the Father, rather than being unbegotten, as the Father is.

This doctrine simply does not work; it contradicts the holy scriptures, our divine, inspired source of knowledge in such matters.

The holy scriptures teach us that God (the one God, the Father) is omniscient; He knows all things perfectly and unchangingly. “God is greater than our heart and knows all things.” 1 John 3:20 NASB. “Great is our Lord and abundant in strength; His understanding is infinite.” Psalm 147:5 NASB. The Son, on the other hand, evidently did not know all things when He said “But of that day and hour no one knows, not even the angels of heaven, nor the Son, but the Father alone.” Matthew 24:36 NASB. Someone might object that the Son only said this in reference to His human nature, and that while His human nature did not know, His divine nature did; to this I respond that natures do not know anything, nor do they possess any consciousness or mind of their own, but rather, persons do. So long then, as it is acknowledged that the Lord Jesus Christ, the Son of the living God, is one person, not two, it must be admitted that He, that is, the person Himself, did not know all things, while the Father in His own person always does know all things.

The holy scriptures also teach us to believe that God is immutable; He does not change. “For I, the Lord, do not change; therefore you, O sons of Jacob, are not consumed.” Malachi 3:6 NASB. “Every good thing given and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shifting shadow.” James 1:17 NASB. The Son, however, has often changed since the foundation of the world, although He has now come to change no more, as having been perfected. For the Son changed to take on various forms to appear to men in the Old Testament, as the Angel (that is, Messenger) of the Lord. He appeared as a man to Abraham; He appeared in fire to Moses at the burning bush; in the form of man He again wrestled with Jacob; and in the form of God He was seen by Moses, Aaron, and the elders of Israel on Sinai, and again, in that same glory, by Isaiah. But more on these appearances later. And at last, He took on human flesh from the virgin Mary, and in that flesh grew, and matured, and died, and rose from the dead.

Surely no thinking man can regard such actions as not involving change in the Son’s own person; who will be so insane as to say that He is the same, and unchanged, after He has taken a human body into the unity of His person, as He was before, when he had no flesh? One might respond that the Logos Himself, considered in His capacity as Logos specifically, did not suffer change in taking on flesh. To which I say, such may well be the case; yet when we consider not merely the part of Him that was the Logos, but His person on the whole, it cannot be avoided that, as a person, to go from having no body, to having a body, is a change. The Son then, was capable of changing, and did so, only upon His perfection coming finally to the state of immutability of which it is said that “Jesus Christ is the same yesterday and today and forever.” Hebrew 13:8 NASB.

The Father then, is entirely unchanging and immutable, always and eternally being the same without any change or alteration; while the Son indeed, having first been begotten by the Father before the world was, changed into various forms to appear to men, and then for our salvation even took human flesh into the unity of His person, finally coming to change no more once He had risen from the dead. The Father, as being unchanging, would never have appeared to men under various forms, nor would He have taken on flesh; and so there is manifestly a great difference in the attributes of God and His Son shown here by the holy scriptures.

We may also note that the scriptures reveal that the Father is invisible; “Who alone possesses immortality and dwells in unapproachable light, whom no man has seen or can see.” 1 Tim 6:16 NASB. “No one has seen God at any time; the only begotten God who is in the bosom of the Father, He has explained Him.” 1 John 1:18 NASB. “Now to the King eternal, immortal, invisible, the only God, be honor and glory forever and ever. Amen.” 1 Timothy 1:17 NASB. The Son, the only-begotten God, on the other hand, as we have already mentioned above, was often seen by men; He is the visible Image of the invisible God (Col 1:15). As the Angel of the Lord He was the one by Whom God spoke with Abraham (Gen 18), Who rained fire from His Father on Sodom and the surrounding cities (Gen 19:24), Who wrestled with Jacob (Gen 32:22-40), Who spoke to Moses from the burning bush (Ex 3:2), and from the pillar of cloud and of fire (Num 14:14), Who appeared to Joshua as the Captain of the Lord’s hosts (Josh 5:13-15), Who spoke to Hagar (Gen 16:7-14), Gideon (Jud 6:22), Manoah (Jud 13:9-23), and other saints of old (Jud 2:1-6), the Word of the Lord Who came to the prophets and spoke with them (1 Kings 9:9, Isa 38:4, Jer 1:1-2, Ezek 1:3), Whose glory was seen by Isaiah (Isa 6, John 12:41). He was seen then, not only in His incarnation, and after His resurrection, but also beforehand. There is a clear difference then between the Father and the Son, that the one, no one can see or has seen, and the other was seen at many times under different forms, and finally, when He took on flesh for our salvation.

The Father, we read in the scriptures, is absolutely Almighty; the term ‘Almighty’ only ever being used for Him in the whole New Testament, and meaning, literally ‘Ruler over all’ (Gr. ‘Pantokrator’). He is “the Lord God Almighty, Who was, and is, and is to come” (Rev 4:8). He, the living God, the Father of His people, is alone Almighty; “For we are the temple of the living God; just as God said, “I will dwell in them and walk among them; And I will be their God, and they shall be My people. 17 “Therefore, come out from their midst and be separate,” says the Lord. “And do not touch what is unclean; And I will welcome you. 18 “And I will be a father to you, And you shall be sons and daughters to Me,” Says the Lord Almighty.” 2 Corinthians 6:16-18 NASB. And it is clear from the very nature of things, that only one person, one individual being, can be Ruler over all, Almighty, absolutely. For if that one had an equal, neither one having higher authority than the other, and so, neither one ruling over the other, neither would be found Almighty, since neither would truly rule over all, and there would be no supreme Ruler over all at all. If then it is acknowledged that the Father alone is Almighty absolutely, as having dominion not only over the whole universe, but even over the Son (1 Cor 11:3, 1 Cor 15:28), then the Son is not equal to Him in this respect, but subject to Him as to His own God and Father (Rom 15:6). And while the Son, as sharing in the Father’s dominion over the universe, may even be said to be ‘almighty’ in that lesser respect, as He, subordinate to the Father, rules over the universe according to the Father’s will and on His behalf, yet only one of Them is Almighty absolutely, as ruling over all things without exception, namely, the Father, and so, this is shown to be a difference between the Father and the Son also.

We may also note that the scriptures declare that the Father is the one from Whom are all things, as He is the supreme uncaused Cause of all things. “Yet for us there is but one God, the Father, from whom are all things and we exist for Him; and one Lord, Jesus Christ, by whom are all things, and we exist through Him.” 1 Corinthians 8:6 NASB. “For from Him and through Him and to Him are all things. To Him be the glory forever. Amen.” Romans 11:36 NASB. Yet all things are not from the Son in this same way, but are through Him. For the Father is the supreme Cause of all things, having made all things through the Son. Their functions, then, are clearly distinct; the Father acts towards the universe through the mediation of the Son, and not the other way around.

Scripture further reveals to us that God (the Father) is infinite. To be infinite is to be without external bound or limitation; and as God is, as we have said above, the Supreme Ruler over all, and further, the Supreme Cause of all. If then, He is entirely uncaused, and simply eternally and unchangingly is, and is absolutely sovereign over all, it follows that God is subject to no external bound or limitation whatsoever, in either His ontological being, nor in His actions. That He is not bound by anything external to Him in His being and attributes necessarily follows from the fact that as the Cause of all else that exists, He Himself is uncaused; thus no one ever determined what God’s attributed and being would be. He was not made, caused, or begotten according to the will or design of another, but rather He simply is, and is as He is, eternally and unchangingly, without any cause, source, or origin. This is a respect in which God is totally unique compared to everything else in existence, for everything else, including His own Son, does owe its cause and origin, and thus, its being and attributes, to Him. All that God caused has its being and attributes according to His will. Likewise, since God is sovereign over all, there is nothing external to Him binding His actions; He is not subject to another, so as to have anything required of Him by another, but is totally free. “Whatever the Lord pleases, He does, In heaven and in earth, in the seas and in all deeps.” Psalm 135:6 NASB. There is none to place Him under obligation or law; His future is not predestined by another.

God’s absolute freedom and infinitude in these respects is unique to Him, as we have said, and so, is not shared by His Son. While of the Father is is written “But our God is in the heavens; He does whatever He pleases.” Psalm 115:3 NASB, the Son declares “Truly, truly, I say to you, the Son can do nothing of Himself, unless it is something He sees the Father doing; for whatever the Father does, these things the Son also does in like manner.” John 5:19 NASB. He says, “I can do nothing on My own initiative. As I hear, I judge; and My judgment is just, because I do not seek My own will, but the will of Him who sent Me.” John 5:30 NASB. The Son clearly teaches us to believe that He is limited by the Father’s will. In this the Son clearly stands in contrast to the Father then, that while the Father is absolutely free and infinite, not bound or subject to the will of another, the Son is indeed limited by the Father, as respects both His being and attributes, which He has from the Father, and as respects His actions.

What more shall we say? Scripture teaches that the Father is alone good (Mark 10:18), alone holy (Rev 15:4), “the only wise God” (Rom 16:27), “the blessed and only Sovereign” (1 Tim 6:15), “the only true God” (Jn 17:3). It says these things on account the the surpassing and incomparable greatness of God, for in contrast to all else which is good, and holy, and wise, and which possesses sovereignty, and divinity, it is as though He alone is such things, and that all else is as nothing in these things, in comparison to Him Who is incomparably greater than all. Not only does the Son declare that His Father is “greater than all” (Jn 10:29), and “greater than I” (Jn 14:28), but even declares Him to be incomparably greater than all; for He says to the Father in the Psalm “There is none to compare with You” Psalm 40:5 NASB. God then has no equal, and the Son is not equal to Him in these attributes, as He is greater than the Son in goodness, and holiness, and wisdom, and sovereignty, and divinity -not that the Son is not very great in all these things- but His Father is still greater, as being incomparably greater than all, even greater than His Son. For as the Son says “There is none to compare with You.” Psalm 40:5 NASB. And God testifies Himself, saying “To whom then will you liken Me, That I would be his equal?” says the Holy One.” Isaiah 40:25 NASB, and “To whom would you liken Me And make Me equal and compare Me, That we would be alike?” Isaiah 46:5 NASB.

Who then will make the Son equal with the Father, in contradiction to the words of both the Father and the Son, Who both testify to the truth that God has no equal, but is incomparably greater than all? Where is this teaching that there is another Who is identical to God and equal with Him in all respects and in all attributes, except that He is begotten while God the Father is unbegotten? Who can read these things and not recognize that rightly did Ulfilas characterize this a “devilish invention and doctrine of demons”, on account of how blasphemous these things are to God? For in supposing that they exalt the Son with this doctrine, really, they give the Son a false and empty honor (as no honor not founded in truth has any weight to it) and rather blaspheme the one the Lord Jesus Christ teaches us to call “the only true God”, by making Him Who is incomparably greater than all out to merely be one of two or three of a kind.

The doctrine of generic co-essentiality, then, that ‘the Son is identical to the Father in all His attributes, except that He is begotten rather than unbegotten’, is shown to be quite unbiblical, and ultimately, quite blasphemous. I do not say that it is heresy, for it does not violate that ancient rule of faith; but it is a false and harmful doctrine, nonetheless, and one quite clearly opposed to the teaching of the scriptures themselves.

Thoughts and Questions on the Councils of Arminium and Seleucia

-The joint councils of Arminium and Seleucia met in 359 to resolve the ongoing trinitarian debates of the fourth century. The council of Nicea had succeeded in largely nullifying the threat of Arianism, but also, by introducing highly philosophical, extra-biblical, controversial language of ‘ousia’, ‘being’, or ‘substance’, had continued to be a source of controversy to the churches of the Roman empire.

-The joint councils of Arminium and Seleucia were called by emperor Constantius to settle the ongoing debates that divided the church. These councils were intended to be ecumenical, and their decision was one. They met in separate locations sheerly for the convenience of the bishops attending. The council of Arminium alone was said to have included 330 bishops, making it larger than Nicea, and over twice as large as the first council of Constantinople.

-The decision of these councils, with the approval of the emperor, was to remove all language of ‘ousia’ from the church’s dogma, and to ban extra-biblical speculation on what the metaphysical relation of the Son’s nature to that of the Father is. The Son was to be described as “like to the Father Who begat Him, according to the scriptures”, and after a brief creed, their decision included this statement: “But the name of ‘essence,’ which was set down by the fathers in simplicity, and, being unknown by the people, caused offense, because the Scriptures do not contain it, it has seemed good to abolish, and for the future to make no mention of it at all; since the divine scriptures have made no mention of the essence of Father and Son. For neither ought ‘subsistence’ to be named concerning Father, Son and Holy Ghost. But we say that the Son is like the Father, as the divine Scriptures say and teach; and all the heresies, both those which have been already condemned, and whatever are of modern date, being contrary to this published statement, be they anathema.”

-Although the council proscribed all previously condemned heresies, and thus that of Arius as well, it has been slandered by the Romans and homoousians as an Arian council, and a victory of Arianism.


1) Were not the councils of Arminium and Seleucia faithful to the instruction of the apostle Paul in holding fast to “the pattern of sound words” given in the scriptures?

2) Do not the councils of Arminium and Seleucia constitute a valid second ecumenical council?

3) How can a decision which maintained the anathemas of previous councils against Arianism, and thus continued to proscribe Arians from communion, be Arian? How can the continued excommunication of Arians represent a victory of that heresy?

4) If, as the Romans and homoousians have so been inclined to say, the councils pronounced a sentence in favor of Arianism, did not the churches err in their official teachings?

5) Is a refusal to call the Son ‘homoousias’ with the Father not damnable heresy, as the official decisions of later councils say?

6) If the church then supposedly erred in its official teachings in rejecting the word ‘homoousias’, in a damnable way, did the churches of the Roman empire not, according to that view, go apostate in 359? How can churches not be said to go apostate, if they embrace damnable heresy as their official teaching?

7) If the church then erred, as the homoousians are inclined to say, why then do the Eastern Orthodox, the Romans, the Coptics, and the other ancient communions hold that the church cannot err in its official teaching, since it is guided by the Spirit to be free from error?

8) If it be argued that the pressure of the Roman government on the church is what secured the decision of these councils, and thus they are invalid, why can it not equally be argued that the decisions of Nicea and Constantinople may likewise be disregarded on that same basis, since in both the Emperors were intimately involved?

9) If it will be argued in defense of the councils of Nicea and Constantinople that since the churches could not be compelled to compromise their faith in the face of three hundred years of open and brutal persecutions, therefore they surely would not have bent to the will of the emperors against the true sentiments of the churches, and so the involvement of the emperors in these councils cannot be said to invalidate their decisions, must not the same argument be equally valid when applied to the councils of Arminium and Seleucia?

10) If the churches of the fourth century believed, by way of an apostolic tradition, that ecumenical councils cannot err, as the Eastern Orthodox hold, why then were such a great multitude of bishops from both the eastern and western reaches of the Roman Empire willing to declare that Nicea had erred in introducing the term ‘homoousias’ into the church’s dogma? Does not such a decision manifestly testify that the ancient churches held no such sentiment about ecumenical councils?

11) If the approval of the Pope of Rome were known by the churches to be necessary for the decision of a council to be legitimate, as the papists claim, why then did the churches of the Roman empire give their acceptance to the decision of the councils of Arminium and Seleucia, which the Pope refused to consent to, and was therefore deposed?

12) Is it not conducive to the peace and unity of the churches to impose nothing on them beyond what can be proven from the scriptures, as the councils of Arminium and Seleucia sought to do?

13) If it is to be counted as a great sin to charge the churches with having apostatized, as some count it, are not those then who, while accepting the 7 so-called ecumenical councils, denounce those of Arminium  and Seleucia as Arian, guilty of the same supposed impiety they charge others with, since they must regard the churches as having apostatized for over twenty years following the councils of Arminium and Seleucia?

14) Is it not manifestly an impossible position to say that the church cannot err in its official teaching, when at Nicea, the church officially taught that the Son is ‘homoousias’ with the Father, and yet also officially taught at the councils of Arminium and Seleucia that it is improper to teach that the Son is ‘homoousias’ with the Father, and banned such speculation? Likewise is it not a manifest contradiction when the church officially taught at Arminium and Seleucia that Nicea had erred in introducing ‘homoousias’, while about twenty years later the churches officially taught that Nicea was correct in doing so, and made ‘homoousias’ a dogmatic standard again? How can two mutually exclusive positions be officially taught by the churches at different times, and it not require that in at least one of those decisions, the churches erred?

15) Are not those churches which hold sola scriptura, while requiring a dogmatic confession of ‘homoousias’ from their members, manifestly acting in self-contradiction?

16) Did not the Homoians who held to the decision of the councils of Arminium and Seleucia faithfully hold and teach a form of sola scriptura some one thousand years before the Protestant Reformation, and apply that principle more consistently than the latter?

17) According to the standard of the holy scriptures alone, can there be any insufficiency ascribed to describing the Son as “like the Father as the scriptures say and teach”?

18) If the Son is homoousias with the Father, and does by virtue of His divine nativity before the ages share one and the same metaphysical nature and essence with the Father, is He not “like the Father”? For He is another person from the Father; begotten, not unbegotten; Son, not Father. And so He cannot be said to be the same person, nor a completely identical person, but a like person.

19) Is not the confession of the Son being “like the Father, according to the scriptures”, without any mention of metaphysical nature, a more scriptural confession than describing the Son as homoousias?

20) Is it not better suited to the capacity of the simple and less-educated to describe the Son as being like the Father, as the scriptures teach, than to demand that the simple must learn platonic or aristotelian metaphysics to be good Christians?

21) Is it not better suited to the teaching of scripture, that while the Son is the exact representation of the Father’s person, the brightness of His glory, Who has life in Himself as He has life in Himself, Who is eternal and before all creation with the Father, through Whom all creation was made, and is the Image of the invisible God, and so not invisible as His Father is, to simply describe the Son as being “like the Father, according to the scriptures”, than to demand a philosophical confession which seems to contradict that the Son is from eternity the visible Image of the invisible God?

22) Has not the historic teaching of most, if not all homoousians, such as Hilary and Augustine, been that since the Son is of the same divine metaphysical nature as the Father, He must according to that nature be invisible?

23) And is not such teaching manifestly contradictory not only to the plain sense of the scriptures, but to the ecclesiastical tradition of the ante-nicene church, which taught that the Son, as the Angel of the Lord, was visible in His pre-incarnate nature? Did not those same ante-nicenes argue for the identity of the Angel of the Lord being the Son on the very basis of there being a difference between the Father and the Son, that the Father cannot be seen, but the Son can be, and on that very basis argue that the Son was the Angel of the Lord?

These questions are more intended to be rhetorical than to solicit an answer; answers and comments, however, are welcome.

Semi-modalism in the Liturgy of St. James

The Liturgy of St. James is renowned as being one of the oldest liturgies in Christianity, supposedly going back all the way to the apostle James the brother of the Lord. Although the liturgy is reputed to have an apostolic origin, it continued to see modification for several centuries, the version used today perhaps dating back to the fifth or sixth centuries.

Because of such modifications to an ancient document, it is of course difficult to ever say with absolute certainty what is original and what is not. Certain things can easily be conjectured to be additions however as they bear the mark of later theological controversies that a first century liturgy would not have spoken to. The language in many places is seen to date from the post-nicene era.

One such instance of an anachronism in the liturgy is that its second paragraph is expressly semi-modalistic, something otherwise unheard of in orthodox churches in the ante-nicene era. It says:

“II Glory to the Father, and to the Son, and to the Holy Spirit, the triune light of the Godhead, which is unity subsisting in trinity, divided, yet indivisible: for the Trinity is the one God Almighty, whose glory the heavens declare, and the earth His dominion, and the sea His might, and every sentient and intellectual creature at all times proclaims His majesty: for all glory becomes Him, and honour and might, greatness and magnificence, now and ever, and to all eternity. Amen.”

A more explicitly semi-modalistic statement would only be possible if it came right out and called the Trinity as a whole a “person” (like Cornelius Van Til did: ).

We see that this liturgy expressly contradicts the Nicene Creed, which begins by defining the one God of the Christian faith as the person of the Father saying “We believe in one God, the Father Almighty…” Instead the Liturgy defines the one God as the Trinity itself.

That the Trinity is treated as a single person is also abundantly clear, as it goes on to use singular personal pronouns such as “his” for the Trinity several times.

It is sad to see semi-modalism encapsulated in the Liturgy which is perhaps in its original form the oldest liturgy we have still in use. The liturgy of St. James is commonly used by various Eastern churches, including the Syriac Orthodox church and occasionally by the Eastern Orthodox Church, which despite this part of its liturgy, is actually making great strides in returning to classical trinitarianism such as that articulated by the Nicene Creed (see: ).

Fr. John Behr on the One God being the Person of the Father in Particular

In my last post, I shared quotes from several prominent Eastern Orthodox theologians speaking on the patristic view of the Trinity and the matter of the one God of the Christian faith being the person of the Father in particular (see

I wanted to now share an article written by another Eastern Orthodox theologian, Fr. John Behr: here.

In this article Fr. Behr briefly and clearly sheds some light on the way the Greek church fathers articulated the doctrine of the Trinity, and notes:

“The Father alone is the one true God. This keeps to the structure of the New Testament language about God, where with only a few exceptions, the world “God” (theos) with an article (and so being used, in Greek, as a proper noun) is only applied to the one whom Jesus calls Father, the God spoken of in the scriptures. This same fact is preserved in all ancient creeds, which begin: I believe in one God, the Father…

“For us there is one God, the Father… and one Lord Jesus Christ” (1 Cor 8:6).”

I have found Fr. Behr’s careful and thought-provoking analysis of these issues helpful, and hope you will as well.


Modern Eastern Orthodox Theologians on the One God being the Person of the Father

In recent years there has been something of a revival of aspects of classical trinitarianism in Eastern Orthodoxy. Several prominent EO theologians have argued for a return to a Nicene understanding of the Trinity and the belief that the one God is the Father.

As in the last few centuries the Eastern church has undergone what some have referred to as a “patristic renaissance” it is no surprise to see their theology has moving away from a semi-modalistic direction and returning to what the Ante-Nicene and Nicene Fathers articulated regarding the one God being the person of the Father in particular.

I wanted to share a few quotes from some of these theologians below:

John Meyendorff:

The same personalistic emphasis appears in the Greek Fathers’ insistence on the “monarchy” of the Father. Contrary to the concept which prevailed in the post-Augustinian West and in Latin Scholasticism, Greek theology attributes the origin of hypostatic “subsistence” to the hypostasis of the Father—not to the common essence. The Father is the “cause” (aitia) and the “principle” (archē) of the divine nature, which is in the Son and in the Spirit. What is even more striking is the fact that this “monarchy” of the Father is constantly used by the Cappadocian Fathers against those who accuse them of “tritheism”: “God is one,” writes Basil, “because the Father is one.” (Byzantine Theology, 2nd ed, 1983, page 183)

John Zizioulas:

Among the Greek Fathers the unity of God, the one God, and the ontological “principal” or “cause” of the being and life of God does not consist in the one substance of God but in the hypostasis, that is, the person of the Father. The one God is not the one substance but the Father, who is the “cause” both of the generation of the Son and the procession of the Spirit. (Being As Communion, 1985, pages 40-41)

Thomas Hopko:

“… in the Bible, in the creeds, and in the Liturgy, it’s very important, really critically important, to note and to affirm and to remember that the one God in whom we believe, strictly speaking, is not the Holy Trinity. The one God is God the Father. In the Bible, the one God is the Father of Jesus Christ. He is God who sends his only-begotten Son into the world, and Jesus Christ is the Son of God. Then, of course, in a parallel manner, the Spirit, the Holy Spirit, is the Spirit of God, that the Holy Spirit, being the Spirit of God, is therefore also the Spirit of Christ, the Messiah, because the Christ is the Son of God, upon whom God the Father sends and affirms his Holy Spirit.” (From the online transcript of the podcast, The Holy Trinity)