16. Wherefore let the Arians observe, how impious they are in calling in question our hope and the object of our desires. And since they are wont to cry out on this point above all others, saying that Christ is distinct from the only and true God, let us confute their impious ideas so far as lies in our power.
17. For on this point they ought rather to understand, that this is the benefit, this the reward of perfect virtue, namely, this divine and incomparable gift, that we may know Christ together with the Father, and not separate the Son from the Father; as also the Scriptures do not separate them. For the following tells rather for the unity than for the diversity of the Divine Majesty, namely, that the knowledge of the Father and of the Son gives us the same recompense, and one and the same honour; which reward no man will have but he that has known both the Father and the Son. For as the knowledge of the Father procures eternal life, so also does the knowledge of the Son.
18. Therefore as the Evangelist forthwith at the outset joined the Word with God the Father in his devout confession of faith, saying: "And the Word was with God;"  and here too, in writing the words of the Lord: "That they may know Thee, the only true God, and Jesus Christ Whom Thou hast sent,"  he has undoubtedly, by thus connecting Them, bound together the Father and the Son, so that no one may separate Christ as true God from the majesty of the Father, for union does not dissever.
19. Therefore in saying, "That they may know Thee, the only true God, and Jesus Christ Whom Thou hast sent," he put an end to the Sabellians, and has also put the Jews out of court, -- those at any rate who heard him speak; so that the former might not suppose the Same to be the Father as the Son, which they might have done if he had not added also Christ, and that the latter might not sever the Son from the Father.
20. But, I ask, why do they not think we ought to gather and understand this from what has been already said; that as he has declared the Father to be only, true God, so we may understand Jesus Christ also to be only, true God? For it could not be expressed in any other way, for fear he might seem to be speaking of two Gods. For neither do we speak of two Gods; and yet we confess the Son to be of the same Godhead with the Father.
21. May we ask, therefore, on what grounds they think a distinction is made in the Godhead, and whether they deny Christ to be God? But they cannot deny it. Do they deny Him to be true God? But if they deny Him to be true God, let them say whether they declare Him to be a false God, or God by appellation only. For according to the Scriptures the word "God" is used either of the true God, or by appellation only, or of a false god. True God as the Father; God by appellation as the saints; a false god like the demons and idols. Let them say then how they will acknowledge and describe the Son of God. Do they suppose the name of God to have been falsely assumed; or was there in truth merely an indwelling of God within Him, as it were by appellation only?
22. I do not think they can say the name was falsely assumed, and so involve themselves in the open wickedness of blasphemy; lest they should betray themselves on the one hand to the demons and idols, and on the other to Christ, by insinuating that the name of God was falsely given to Him. But if they think He is called God because He had an indwelling of the Godhead within Him, -- as many holy men were (for the Scripture calls them Gods to whom the word of God came),  -- they do not place Him before other men, but think He is to be compared with them; so that they consider Him to be the same as He has granted other men to be, even as He says to Moses: "I have made thee a god unto Pharaoh."  Wherefore it is also said in the Psalms: "I have said, ye are gods." 
23. This idea of these blasphemers Paul puts aside; for he said: "For though there be that are called gods, whether in heaven or in earth."  He said not: "There be gods," but "There be that are called gods." But "Christ," as it is written, "is the same yesterday and to-day."  "He is," it says; that is, not only in name but also in truth.
24. And well is it written: "He is the same yesterday and to-day," so that the impiety of Arius might find no room to pile up its profanity. For he, in reading in the second psalm of the Father saying to the Son, "Thou art My Son, this day have I begotten Thee,"  noted the word "to-day," not "yesterday," referring this which was spoken of the assumption of our flesh to the eternity of the divine generation; of which Paul also says in the Acts of the Apostles: "And we declare unto you the promise which was made to our fathers: for God has fulfilled the same to our children, in that He hath raised up the Lord Jesus Christ again, as it is written in the second psalm: Thou art My Son, this day have I begotten Thee."  Thus the Apostle, filled with the Holy Ghost, in order that he might destroy that fierce madness of his, said: "The same, yesterday, to-day, and for ever." "Yesterday" on account of His eternity; "to-day" on account of His taking to Himself a human body.
25. Christ therefore is, and always is; for He, Who is, always is. And Christ always is, of Whom Moses says: "He that is hath sent me."  Gabriel indeed was, Raphael was, the angels were; but they who sometime have not been are by no means with equal reason said always to be. But Christ, as we read, "was not it is, and, it is not, but, it is was in Him."  Wherefore it is the property of God alone to be, Who ever is.
26. Therefore if they dare not say He is God by appellation, and it is a mark of deep impiety to say He is a false god, it remains that He is true God, not unlike to the true Father, but equal to Him. And as He sanctifies and justifies whom He will,  not by assuming that power from without Himself, but having within Himself the power of sanctification, how is He not true God? For the Apostle called Him indeed true God, Who according to His nature was God, as it is written: "Howbeit then, when ye knew not God, ye did service unto them, who by nature were not gods;"  that is, who could not be true gods, for this title by no means belonged to them by nature.
 S. John 1:1.  S. John 17:3.  S. John 10:35.  Exodus 7:1.  Psalm 82:6.  1 Corinthians 8:5.  Hebrews 13:8.  Psalm 2:7.  Acts 13:32, 33.  Exodus 3:14.  2 Corinthians 1:19.  Romans 9:18.  Galatians 4:8.
 S. John 17:3.
 S. John 10:35.
 Exodus 7:1.
 Psalm 82:6.
 1 Corinthians 8:5.
 Hebrews 13:8.
 Psalm 2:7.
 Acts 13:32, 33.
 Exodus 3:14.
 2 Corinthians 1:19.
 Romans 9:18.
 Galatians 4:8.