On the Incarnation of the Lord (Against Nestorius)

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!