Creeds published at Sirmium in Presence of the Emperor Constantius
It is evident that there is one God, the Father Almighty, according as it is declared over the whole world; and his only-begotten Son Jesus Christ, our Lord, God, and Saviour, begotten of him before the ages. But we ought not to say that there are two Gods, since the Lord himself has said 'I go unto my Father and your Father, and unto my God and your God.' Therefore he is God even of all, as the apostle also taught, 'Is he the God of the Jews only? Is he not also of the Gentiles? Yea of the Gentiles also; seeing that it is one God who shall justify the circumcision by faith.' And in all other matters there is agreement, nor is there any ambiguity. But since it troubles very many to understand about that which is termed substantia in Latin, and ousia in Greek; that is to say, in order to mark the sense more accurately, the word homoousion or homoiousion, it is altogether desirable that none of these terms should be mentioned: nor should they be preached on in the church, for this reason, that nothing is recorded concerning them in the holy Scriptures; and because these things are above the knowledge of mankind and human capacity, and that no one can explain the Son's generation, of which it is written, 'And who shall declare his generation?' It is manifest that the Father only knows in what way he begot the Son; and again the Son, how he was begotten by the Father. But no one can doubt that the Father is greater in honor, dignity, and divinity, and in the very name of Father; the Son himself testifying 'My Father who has sent me is greater than I.' And no one is ignorant that this is also catholic doctrine, that there are two persons of the Father and Son, and that the Father is the greater: but that the Son is subject, together with all things which the Father has subjected to him. That the Father had no beginning, and is invisible, immortal, and impassible: but that the Son was begotten of the Father, God of God, Light of Light; and that no one comprehends his generation, as was before said, but the Father alone. That the Son himself, our Lord and God, took flesh or a body, that is to say human nature, according as the angel brought glad tidings: and as the whole Scriptures teaches, and especially the apostle who was the great teacher of the Gentiles, Christ assumed the human nature through which he suffered, from the Virgin Mary. But the summary and confirmation of the entire faith is, that [the doctrine of] the Trinity should be always maintained, according as we have read in the gospel, 'Go ye and disciple all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit.' Thus the number of the Trinity is complete and perfect. Now the Comforter, the Holy Spirit, sent by the Son, came according to his promise, in order to sanctify and instruct the apostles and all believers.
They endeavored to induce Photinus, even after his deposition, to assent to and subscribe these things, promising to restore him his bishopric, if by recantation he would anathematize the dogma he had invented, and adopt their opinion. But he did not accept their proposal, and on the other hand he challenged them to a disputation: and a day being appointed by the emperor's arrangement, the bishops who were there present assembled, and not a few of the senators, whom the emperor had directed to attend to the discussion. In their presence, Basil, who at that time presided over the church at Ancyra, was appointed to oppose Photinus, and short-hand writers took down their respective speeches. The conflict of arguments on both sides was extremely severe; but Photinus having been worsted, was condemned, and spent the rest of his life in exile, during which time he composed treatises in both languages— for he was not unskilled in Latin— against all heresies, and in favor of his own views. Concerning Photinus let this suffice.
Now the bishops who were convened at Sirmium, were afterwards dissatisfied with that form of the creed which had been promulgated by them in Latin; for after its publication, it appeared to them to contain many contradictions. They therefore endeavored to get it back again from the transcribers; but inasmuch as many secreted it, the emperor by his edicts commanded that the version should be sought for, threatening punishment to any one who should be detected concealing it. These menaces, however, were incapable of suppressing what had already fallen into the hands of many. Let this suffice in regard to these affairs.>
Source: Ecclesiastical History (New Advent)