Eusebius of Caesarea is known as one of the great church historians, and is famous for his Church History, which is often credited both with introducing church history as its own field of study, as well as being invaluable in providing learned and detailed accounts of events, rich with quotations of primary sources.
Eusebius himself, although renowned as a historian and acknowledged as being very learned even by his detractors, has also gained a bad reputation coming down to our own time. This negative reputation usually consists of charges of supporting Arianism, or at least believing some shade of the heresy. Prior to the Nicene Council Eusebius seems to have openly supported Arius, although he did consent to the decision of the Nicene Council and the Creed they composed. Even after the Nicene Council, Eusebius opposed Athanasius of Alexandria and was still regarded as sympathetic to Arianism.
It is important to realistically acknowledge these shortcomings, these sins. Supporting the Arian party was terribly wrong and sinful, and it seems clear that during this period of his life Eusebius fell short of orthodox classical trinitarianism, as we see espoused by Athanasius of Alexandria and Cyril of Jerusalem.
There does, however, seem to be evidence that later in his life, Eusebius repented of this heresy, rejected Arianism, and embraced classical trinitarianism. That this is the case can be seen most clearly from his own words in On Ecclesiastical Theology, a dogmatic work Eusebius authored towards the end of his life, directed against modalism and seeking to give an exposition of trinitarian orthodoxy. In this work, we see teaching consistent with that of other orthodox fathers like Athanasius, and explicit and emphatic denials of the central tenets of Arianism, namely, that the Word was a creature, and that the Son was not co-eternal with the Father.
Instead Eusebius in On Ecclesiastical Theology gives a detailed treatment of trinitarianism, in general agreement with that taught by the orthodox fathers of the ante-nicene era, as well as those of his own nicene era. He teaches the divinity and eternality of the Son, and teaches against both the Arianism he had formerly lent his support to and the modalism that threatened the church of his day. This repentance on Eusebius’s part is cause for great joy; a man who was among the most prestigious church fathers of his day, who had formerly associated with Arianism, in the end rejected and refuted it, dealing a great blow to the Arian cause, and giving support to the cause of trinitarian orthodoxy. We must also care for him as an individual, and rejoice to see his repentance from such great sin.
Yet despite this, many throughout church history have soiled his reputation by constantly regarding him as an Arian, on the basis of his former sin. What false and perverse form of Christianity ignores the repentance of a sinner, and after they have turned from their sin and received forgiveness through Christ, still regards them as a sinner, I do not know. For all have sinned and fallen short of the glory of God; and while we were yet sinners, after our repentance the scriptures no longer call us sinners, but rather speak thus: “Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, 10 nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God. 11 Such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.” (1 Cor 6:9-11 NASB). Scripture does not then teach that all those who once sinned “will not inherit the kingdom of God”, but rather says to those who have repented “Such were some of you; but you were washed”.
And if anyone will object that this passage of scripture speaks of sins committed before baptism, let them remember King David, who is numbered among the saints, and not dishonorably, although he murdered a man and committed adultery with his wife. The same David, the scripture later speaks of as having repented: “I acknowledged my sin to You, And my iniquity I did not hide; I said, “I will confess my transgressions to the Lord”; And You forgave the guilt of my sin. Selah.” (Psalm 32:5 NASB)
Those then, who after having been regenerated, have sinned, and erred, even very grievously, when they have repented, and again been restored in the sight of God and men, ought not to be slandered for their former sins, as though they had not repented, and disowned their former sins.
But besides those who slander the man for the sins he repented of in respect to Arius, there are also those who hold him in low esteem for regarding images of Christ as unfitting; and for this reason many who want to discredit him have seized upon his former Arianism as a grounds to dismiss all that the man ever taught, as though what he taught after he repented ought not be received as the writings of any other orthodox church father.
And yet even his greatest detractors will make use of his Church History; for no one can fairly deny him to have been a capable scholar and historian. So much then, for the controversy that for over a millennia has surrounded the reputation of Eusebius.
Having put aside his former Arianism and embraced orthodoxy, Eusebius provides us with a useful treatment of trinitarianism in his On Ecclesiastical Theology, in which he clearly explains his belief, in agreement with that of the rest of the church, that the one God of the Christian faith is the person of the Father in particular:
“The children of the Jews first received the confession of the one God in opposition to the polytheistic error of the Greeks. But the saving grace of recognizing that the same [God] is also Father of an only-begotten Son has been given to the Church as a special privilege. For as Son it knows Jesus Christ alone and no other, not according to generation of the flesh that he assumed (for it has been taught to call this flesh the “form of a slave” and “Son of Man”), but according to his [generation] before all ages from God himself and the Father, [which is] unknowable to all. According to this [generation from God] the fullness of the paternal divinity also made him, the Son, God, and so as a result he possesses a divinity that is not his own, [not] one separated from that of the Father, nor one that is without source and that is unbegotten, nor one that is foreign, from somewhere else, and different from the Father’s. Rather, he is filled with divinity by participating in the paternal [divinity] itself, which pours into him as from a fountain. For the great Apostle taught that “in him alone dwells the fulness” of the paternal “divinity.” For this reason then, one God is proclaimed by the Church of God, “and there is no other beside him,” but also one only-begotten Son of God, the image of the paternal divinity, who, because of this, is God.” (On Ecclesiastical Theology, Book I, Ch 2)
“If the notion of proclaiming two gods makes them afraid, let them know that even when the Son is confessed by us to be God, the former [namely, the Father] would still be the one and only God, the only one without source and unbegotten, the one who possesses the divinity as his own, and who has become the cause of being in such a way for the Son himself.
Even the Son himself confesses that he lives because of [him], saying outright, “As the living Father sent me, and I live because of the Father,” and, “For as the Father has life in himself, so also he has given to the Son to have life in Himself.” For this reason, he also teaches that the Father is both our God and his God, when he says, “I go to my Father and to your Father and to my God and to your God.” The great Apostle teaches that God is the head of the Son and the Son is the head of the Church, in one place saying, “the head of Christ is God,” and in another asserting about the Son, “and he made him head over all things for the Church, which is his body.” Therefore, he himself would be the originator and head of the Church while the Father would also be his head. In this way the Father of the only-begotten Son is one God, and the head of even Christ himself is one. Since there is one source and head, how could there be two gods, and not one, that one alone, who acknowledges no higher being nor other cause than himself, who possesses the divinity of monarchial authority as his own, without source and unbegotten and who has given a share of his own divinity and life to the Son, who through him [the Son] has brought all things into existence, who sends him, who gives commands to him, who enjoins him, who teaches, who hands all things over to him, who glorifies him, who exalts him in the highest, who revealed him as king of the universe, who gives all judgement to him, who wishes that we also obey him, who encourages him to take up his throne at the right hand of his magnificence when he addresses him and says, “Sit at my right hand,” the one who, for all these reasons, also exists as God of the Son himself, in obedience to whom his only-begotten child “emptied himself, humbled himself, took on the form of a slave and became obedient unto death,” to whom he [the Son] also prayed, to whom he renders obedience when he [the Father] commands, to whom he also gives thanks, whom he also teaches us to consider “the only true God”, whom he confesses to be greater than himself, whom, in addition to all these features, he wishes us to know is also his God?” (On Ecclesiastical Theology, Book I, Ch 11)
“But the Church of God also acknowledges that the monad is indivisible, confessing one source, the one God who is unbegotten and without source, but also deems the only-begotten Son who is born from him, truly existing and living and subsisting, as Savior, although he is neither without source nor unbegotten (so as not to posit two sources and two gods), but begotten from the Father himself and having the one who has begotten him as source. For this reason, it has received the belief in one God the Father, who rules over all, and in Jesus Christ our Lord, the only-begotten Son of God, this holy and mystical faith providing regeneration in Christ to those who are enlightened through it… But God, being an indivisible monad, begot his only-begotten Son from himself, neither being divided nor undergoing alteration, change, flux, or any suffering.” (On Ecclesiastical Theology, Book 2, Ch 6)
“But are you afraid, man, lest, having confessed that there are two hypostases, you introduce two sources and cast aside the monarchical divinity? Well the, learn that because there is one God who is without source and unbegotten, but the Son has been begotten from him, there will be one source and a single monarchy and kingship, since even the Son himself acknowledges his Father as source. “The head of Christ is God,” according to the Apostle.” (On Ecclesiastical Theology, Book 2, Ch 7)
These quotes are provided from a newly published translation of the On Ecclesiastical Theology, released in last month in January of 2018. I recommend the work to anyone interested in reading further of his treatment on this same subject, or interested in Eusebius’s treatment of other subjects such as christology.
All patristic citations taken from:
Eusebius Pamphilius, On Ecclesiastical Theology, trans. Kelly McCarthy Sproerl and Markus Vinzent (Washington, D.C.: The Catholic University of America Press, 2017).