On the words of the Gospel, John xii.44, "He that believeth on me, believeth not on me, but on him that sent me." Against a certain expression of Maximinus, a bishop of the Arians, who spread his blasphemy in Africa where he was with the Count Segisvult.
1. What is it, Brethren, which we have heard the Lord saying, "He that believeth on Me, believeth not on Me, but on Him that sent Me"?  It is good for us to believe on Christ, especially seeing that He hath also Himself expressly said this which ye have now heard, that is, that "He had come a Light into the world, and whosoever believeth on Him shall not walk in darkness, but shall have the light of life."  Good then it is to believe on Christ; and a great evil it is not to believe on Christ. But because Christ the Son is, Whatsoever He is, of the Father, but the Father is not of the Son, but is the Father of the Son; He recommends to us indeed faith in Himself, but refers the honour to His Original. 
2. For hold this fast as a firm and settled truth, if ye would continue Catholics, that God the Father begat God the Son without time, and made Him of a Virgin in time. The first nativity exceedeth times; the second nativity enlighteneth times. Yet both nativities are marvellous; the one without a mother, the other without a father. When God begat the Son, He begat Him of Himself, not of a mother; when the Mother gave birth to her Son, she gave Him birth as a Virgin, not by man. He was born of the Father without a beginning; He was born of a mother, as to-day  at an appointed beginning. Born of the Father He made us; born of a mother He re-made us. He was born of the Father, that we might be; He was born of a mother, that we might not be lost. But the Father begat Him equal to Himself, and All Whatsoever the Son is, He hath of the Father. But What God the Father is, He hath not of the Son. Accordingly we say that the Father is God, of none; the Son, God of God. Wherefore all that the Son doeth marvellously, all that He saith truly, He attributeth to Him of whom He is; yet can He not be ought else than He of whom He is. Adam was made a man; he had power to become something other than he was made. For he was made righteous, and he had power to become unrighteous. But the Only-Begotten Son of God, What He is, This cannot be changed; He cannot be changed into anything else, cannot be diminished, What He was He cannot but be, He cannot but be equal to the Father. But undoubtedly He who gave all things to the Son by His Birth, gave it to One not needing ought; without doubt this very equality too with the Father, the Father gave to the Son. How did the Father give It? did He beget Him less, and add to Him to complete His Form, that He might make Him equal? If he had done this, He would have given it to one in need. But I have told you already what ye ought most firmly to hold fast, that is, that All That the Son is, the Father gave Him, gave Him, that is, by His Birth, not as in need of ought. If He gave it to Him by His Birth, and not as in need, then doubtless He both gave Him equality, and in giving Him equality, begat Him equal. And although the One be One Person, and the Other Another; yet is not the One one thing, and the Other another; but What the One is, That the Other also. He who is the One, is not the Other; but What the One, That too the Other.
3. "He Who sent Me," saith He, ye have heard it; "He Who sent Me," saith He, "He gave Me a commandment what I should say, and what I should speak; and I know that His commandment is life everlasting."  It is John's Gospel, hold it fast. "He Who sent Me, He gave Me a commandment what I should say, and what I should speak; and I know that His commandment is life everlasting." O that He would grant me to say what I wish! For my poverty and His abundance straiteneth me. "He," saith He, "gave Me a commandment, what I should say, and what I should speak; and I know that His commandment is life everlasting." Search in the Epistle of this John the Evangelist for what he hath said of Christ. "Let us believe," he says, "His True Son Jesus Christ. This is the True God and Everlasting Life."  What is, "The True God, and Everlasting Life"? The True Son of God is the "the True God, and Everlasting Life." Why did He say, "On His True Son"? Because God hath many sons, therefore was He to be distinguished, by adding that He was the True Son. Not by simply saying that He is the Son; but by adding, as I have said, that He is the True Son; therefore He was to be distinguished, because of the many sons which God hath. For we are sons by grace, He by Nature. We made by the Father through Him; He Himself That Which the Father is; are we too That Which God is?
4. But some man coming across us, knowing not what he is saying, says, "For this reason was it said, "I and My Father are One;  for that They have with One Another an agreement of will, not because the Nature of the Son is the Very Same as the Nature of the Father. For the Apostles too (now this is what he said,  not I), for the Apostles too are one with the Father and the Son." Horrible blasphemy! "And the Apostles," says he, "are one with the Father and the Son, in that they obey the will of the Father and the Son." Has he dared to say this? Let Paul then say, "I and God are one." Let Peter say it, let every one of the Prophets say, "I and God are one." They do not say it; God forbid they should. They know that they are a different nature, a nature that needeth to be saved; they know that they are a different nature, a nature that needeth to be enlightened. No one says, "I and God are one." Whatsoever progress he may make, howsoever he may surpass others in holiness, with how great eminence soever of virtue he may excel, he never saith, "I and God are one;" for if he have excellence, and therefore saith it; by saying it, he loseth what he had.
5. Believe then that the Son is equal with the Father; but yet that the Son is of the Father; but the Father not of the Son. The Original is with the Father, equality with the Son. For if He be not equal, He is not a true Son. For what are we saying, Brethren? If He is not equal, He is less; if He is less, I ask the nature that needeth to be saved, in its misbelief, "how is He born less?" Answer, Doth He as being less grow or not? If He groweth, then the Father groweth old. But if He will ever be what He was born; if He was born less, He will continue less; with this His loss He will be perfect; born perfect with this loss of the Father's Form, He is never to attain to the Father's Form. Thus do ye ungodly assail  the Son; thus do ye heretics blaspheme the Son. What then saith the Catholic faith? The Son is God, of God the Father; God the Father, not God of the Son. But God the Son equal with the Father, Born equal; not Born less, not made equal, but Born equal. What the Father is, That is He also who was born. Was the Father ever without the Son? God forbid! Take away your "ever," where there is no time. The Father always, the Son always. The Father without beginning of time, the Son without beginning of time; the Father never before the Son, the Father never without the Son. But yet because the Son is God of God the Father, and the Father God, but not of God the Son; let not the honouring of the Son in the Father displease us. For the honouring of the Son giveth honour to the Father, it diminisheth not His Own Divinity.
6. Because then I was speaking of what I had brought forward, "And I knew," saith He, "that His commandment is everlasting life."  Mark, Brethren, what I am saying; "I know that His commandment is everlasting life." And we read in the same John concerning Christ, "He is The True God and Everlasting Life."  If the Father's commandment is "everlasting Life," and Christ the Son Himself is "everlasting Life;" the Son is Himself the Father's Commandment. For how is not That the Father's Commandment, which is the Father's Word? Or if you take the commandment given to the Son by the Father in a carnal sense, as if the Father said to the Son, "I command Thee this, I wish Thee to do that;" in what words spake He to the Only Word? When He gave commandment to the Word, did He look for words? That the Father's Commandment then is "Life everlasting," and that the Son Himself is "Life everlasting," believe ye and receive, believe and understand, for the Prophet saith, "Unless ye believe ye shall not understand."  Do ye not comprehend? Be enlarged. Hear the Apostle: "Be ye enlarged, bear not the yoke with unbelievers."  They who will not believe this before they comprehend, are unbelievers. And because they have determined to be unbelievers, they will remain in their ignorance. Let them believe then that they may understand. Most certainly the Father's Commandment is "everlasting Life." Therefore the Father's Commandment is the Very Son who was born this day; a Commandment not given in time but a Commandment Born. The Gospel of John exercises our minds, refines  and uncarnalizes them, that of God we may think not after a carnal but a spiritual manner. Let so much then, Brethren, suffice you; lest in length of disputation, the sleep of forgetfulness steal over you.
 John 12:44.  Authorem.  The Bened. conjecture that the word "hodie" here and at the end was added in order to adapt this Sermon to be preached on Christmas Day.  John 12:49, 50.  1 John 5:20.  John 10:30.  Maximinus in his Conference with St. Augustin, and St. Augustin in his Answer, B. ii. cont. Maxim. ch. 22.  Addicitis.  John 12:50.  1 John 5:20.  Isaiah 7:9, Sept.  2 Corinthians 6:13, 14.  Limat.
 The Bened. conjecture that the word "hodie" here and at the end was added in order to adapt this Sermon to be preached on Christmas Day.
 John 12:49, 50.
 1 John 5:20.
 John 10:30.
 Maximinus in his Conference with St. Augustin, and St. Augustin in his Answer, B. ii. cont. Maxim. ch. 22.
 John 12:50.
 1 John 5:20.
 Isaiah 7:9, Sept.
 2 Corinthians 6:13, 14.