By Water & Blood

Book 1, Chapter 7: How the heterodox variously fell away from the theology of the Son

Certain godless men among the heterodox, rejecting the Saviour’s flesh and saying that he was seen upon earth by a kind of appearance of phantasm, were the first to miss the mark of the truth. Others, who accepted the incarnate economy (οἰκονομία) but denied the pre-existent Son of God, devised for themselves, as I said, various pathless ways: some said that he was a mere man of the common nature of all, superior in nothing except so far as he excelled in the advantages of virtue; others taught that the God of the universe himself dwelt in the body, and said that he was styled his own Son because of the economy he underwent as man. These, granting two—God and man—deprived themselves of the third, denying the Saviour himself, the only-begotten Son of God.

Carried away in mind together with these men, Sabellius formerly and Marcellus now have insisted that they know very well the God who is over all, just as the unbelieving Jews do; and they have also confessed the second, the flesh from the holy Virgin. But the third—the very sum and head of the salvation of us all—the Son of God, they have elbowed aside; and since he is light and truth, together with the denial of the Son they have also fallen away from the light of the truth.

Hence you will hear them confessing one God and honoring the Saviour’s flesh, while accepting with voice and lips the Son of God who dwelt in the flesh, but in fact rejecting him. For they ought to have sought a Son of God who truly lives and subsists, being neither the same as the body which he assumed nor the same as God the Father. For neither would anyone speak piously who called the God who is beyond the universe a Son (for whose Son will he be who is clothed with the unoriginate and unbegotten Godhead?), nor will anyone who says that the only-begotten Son of God is himself the Father escape the punishment appointed for blasphemers.