Chapter XIII.
He replies to the objection in which they say that the child born [2563] ought to be of one substance with the mother.
But indeed in your deceit and blasphemy you use a grand argument for denying and attacking the Lord God, when you say that "the child born ought to be of one substance with the mother." [2564] I do not entirely admit it, and maintain that in the matter of the birth of God it would not be observed; for the birth was not so much the work of her who bore Him as of her Son, and He was born as He willed, whose doing it was that He was born. Next, if you say that the child born ought to be of one substance with the parent, I affirm that the Lord Jesus Christ was of one substance with His Father, and also with His mother. For in accordance with the difference of the Persons He showed a likeness to each parent. For according to His Divinity He was of one substance with the Father: but according to the flesh He was of one substance with His mother. Not that it was one Person who was of one substance with the Father, and another who was of one substance with His mother, but because the same Lord Jesus Christ, both born as man, and also being God, had in Him the properties of each parent, and in that He was man He showed a likeness to His human mother, and in that He was God He possessed the very nature of God the Father.
[2563] Nativitas.
[2564] Homoousios parienti debet esse nativitas.
Chapter XIV.
He compares this erroneous view with the teaching of the Pelagians.
Otherwise if Christ who was born of Mary is not the same Person as He who is of God, you certainly make two Christs; after the manner of that abominable error of Pelagius, which in asserting that a mere man was born of the Virgin, said that He was the teacher rather than the redeemer of mankind; for He did not bring to men redemption of life but only an example of how to live, i.e., that by following Him men should do the same sort of things and so come to a similar state. Your blasphemy then has but one source, and the root of the errors is one and the same. They maintain that a mere man was born of Mary: you maintain the same. They sever the Son of man from the Son of God: you do the same. They say that the Saviour was made the Christ by His baptism: you say that in baptism He became the Temple of God. They do not deny that He became God after His Passion: you deny Him even after His ascension. In one point only therefore your perverseness goes beyond theirs, for they seem to blaspheme the Lord on earth, and you even in heaven. We do not deny that you have beaten and outstripped those whom you are copying. They at last cease to deny God; you never do. Although theirs must not altogether be deemed a true confession, as they only allow the glory of Divinity to the Saviour after His Passion, and while they deny that He was God before this, only confess it afterwards: for, as it seems to me, one who denies some part in regard to God, denies Him altogether: and one who does not confess that He ever existed, denies Him forever. Just as you also, even if you were to admit that now in the heavens the Lord Jesus Christ, who was born of the Virgin Mary, is God, would not truly confess Him unless you admitted that He was always God. But indeed you do not want in any point to change or vary your opinion. For you assert that He whom you speak of as born a mere man, is still at the present time not God. O novel and marvellous blasphemy, though with the heretics you assert Him to be man, you do not with the heretics confess Him to be God!
Chapter XV.
He shows that those who patronize this false teaching acknowledge two Christs.
But still, I had begun to say, that as you certainly make out two Christs this very matter must be illustrated and made clear. Tell me, I pray you, you who sever Christ from the Son of God, how can you confess in the Creed that Christ was begotten of God? For you say: "I believe in God the Father, and in Jesus Christ His Son." Here then you have Jesus Christ the Son of God: but you say that it was not the same Son of God who was born of Mary. Therefore there is one Christ of God, and another of Mary. In your view then there are two Christs. For, though in the Creed you do not deny Christ, you say that the Christ of Mary is another than the one whom you confess in the Creed. But perhaps you say that Christ was not begotten of God: how then do you say in the Creed: "I believe in Jesus Christ the Son of God?" You must then either deny the Creed or confess that Christ is the Son of God. But if you confess in the Creed that Christ is the Son of God, you must also confess that the same Christ, the Son of God, is of Mary. Or if you make out another Christ of Mary, you certainly make the blasphemous assertion that there are two Christs.