Nicene and Post-Nicene Fathers, Ser. II, Vol. XI:
The Works of John Cassian.: Chapter I. That Christ, who is God and man in the unity of Person, sprang from Israel and the Virgin Mary according to the flesh.

Chapter I.

That Christ, who is God and man in the unity of Person, sprang from Israel and the Virgin Mary according to the flesh.

That divine teacher of the Churches when in writing to the Romans he was reproving or rather lamenting the unbelief of the Jews, i.e., of his own brethren, made use of these words: “I wished myself,” said he, “to be accursed from Christ, for my brethren, who are my kinsmen according to the flesh, who are Israelites, to whom belongeth the adoption as of children, and the glory, and the testaments, and the giving of the law, and the serp. 563 vice of God, and the promises: whose are the fathers, of whom is Christ according to the flesh, who is over all things, God blessed for ever.” 2418 O, the love of that most faithful Apostle, and most kindly kinsman! who in his infinite charity wished to die—as a kinsman for his relations, and as a master for his disciples. And what then was the reason why he wished to die? Only one; viz., that they might live. But in what did their life consist? Simply in this, as he himself says, that they might recognize a Divine Christ born according to the flesh, of their own flesh. And therefore the Apostle grieved the more, because those who ought to have loved Him the more as sprung from their own stock, failed to understand that He was born of Israel. “Of whom,” said he, “is Christ according to the flesh, who is over all things, God blessed for ever.” Clearly he lays down that from them according to the flesh, was born that Christ who is over all, God blessed for ever. You certainly cannot deny that Christ was born from them according to the flesh. But the same Person, who was born from them, is God. How can you get round this? How can you shuffle out of it? The Apostle says that Christ who was born of Israel according to the flesh, is God. Teach us, if you can, at what time He did not exist. “Of whom,” he says, “is Christ according to the flesh, who is over all, God.” You see that because the Apostle has united and joined together these, “God” cannot possibly be separated from “Christ.” For just as the Apostle declares that Christ is of them, so he asserts that God is in Christ. You must either deny both of these statements, or you must accept both. Christ is said to be born of them according to the flesh: but the same Person is declared by the Apostle to be “God in Christ.” Whence also he says elsewhere: “For God was in Christ, reconciling the world to Himself.” 2419 It is absolutely impossible to separate one from the other. Either deny that Christ sprang from them, or admit that there was born of the virgin God in Christ, “who is,” as he says, “over all, God blessed for ever.”

Footnotes

Rom. ix. 3-5.

2 Cor. v. 19.