7 A little before He said, “My judgment is true; because I am not alone, but I and the Father that sent me:” as if He said, The reason why my judgment is true is, because I am the Son of God, because I speak the truth, because I am truth itself. Those men, understanding Him carnally, said, “Where is your Father?” Now hear, O Arian: “You neither know me, nor my Father;” because, “If you knew me, you would know my Father also.” What does this mean, except “I and the Father are one”? When you see some person like some other—give heed, beloved, it is a common remark; let not that appear to you difficult which you see to be customary,— when, I say, you see some person like another, and you know the person to whom he is like, you say in wonder, “How like this person is to that!” You would not say this unless there were two. Here one who does not know the person to whom you say the other is like remarks, “Is he so like him?” And you answer him: What, do you not know that person? Says he, “No, I do not.” Immediately thou, in order to make known to him the person whom he does not know by means of the person whom he observes before him, answerest, saying, Having seen this man, you have seen the other. You did not, surely, assert that they are one person in saying this, or that they are not two; but made such answer because of the likeness: “If you know the one, you know the other; for they are very like, and there is no difference whatever between them.” Hence also the Lord says, “If you knew me, you would know my Father also;” not that the Son is the Father but like the Father. Let the Arian blush. Thanks be to the Lord that even the Arian is separate from the Sabellian error, and is not a Patripassian: he does not affirm that the Father assumed flesh and came to men, that the Father suffered, rose again, and somehow ascended to Himself; this he does not affirm; he acknowledges with me the Father to be Father, the Son to be Son. But, O brother, you have escaped that shipwreck, why go to the other? Father is Father, Son is Son; why do you affirm that the Son is unlike, that He is different, another substance? If He were unlike, would He say to His disciples, “He that has seen me has seen the Father”? Would He say to the Jews, “If you knew me, you would know my Father also”? How would this be true, unless that other was also true, “I and the Father are one”?
8. “These words spoke Jesus in the treasury, speaking in the temple:” great boldness, without fear. For He could not suffer if He did not will it, since He were not born if He did not will it. What follows then? “And no man laid hold of Him, because His hour was not yet come.” Some, again, when they hear this, believe that the Lord Christ was subject to fate, and say: Behold, Christ is held by fate! O, if your heart were not fatuous, you would not believe in fate. If fate, as some understand it, is derived from fando, that is from speaking, how can the Word of God be held by fate, while all things that are made are in the Word itself? For God has not ordained anything which He did not know beforehand; that which was made was in His Word. The world was made; both was made and was there. How both was made and was there? Because the house which the builder rears, was previously in his art; and there, a better house, without age, without decay: however, to show forth his art, he makes a house; and so, in a manner, a house comes forth from a house; and if the house should fall, the art remains. So were all things that are made with the Word of God; because God made all things in wisdom, and all that He made were known to Him: for He did not learn because He made, but made because He knew. To us they are known, because they are made: to Him, if they had not been known, they would not have been made. Therefore the Word went before. And what was before the Word? Nothing at all. For were there anything before it, it would not have been said, “In the beginning was the Word;” but, In the beginning was the Word made. In short, what says Moses concerning the world? “In the beginning God made the heavens and the earth.” Made what was not: well, if He made what was not, what was there before? “In the beginning was the Word.” And whence came heaven and earth? “All things were made by Him.” Do you then put Christ under fate? Where are the fates? In heaven, do you say, in the order and changes of the stars. How then can fate rule Him by whom the heavens and the stars were made; while your own will, if you think rightly, transcends even the stars? Or, because you know that Christ's flesh was under heaven, is that the reason why you think that Christ's power was put under the heavens?
Source: Tractates on the Gospel of John (New Advent)