Ignatius of Antioch -- Epistle to the Antiochians
Chapter 5. Denunciation of false teachers
Whosoever, therefore, declares that there is but one God, only so as to take away the divinity of Christ, is a devil, and an enemy of all righteousness.
He also that confesses Christ, yet not as the Son of the Maker of the world, but of some other unknown being, different from Him whom the law and the prophets have proclaimed, this man is an instrument of the devil. And he that rejects the incarnation, and is ashamed of the cross for which I am in bonds, this man is antichrist. Moreover, he who affirms Christ to be a mere man is accursed
, according to the [declaration of the] prophet, Jeremiah 17:5 since he puts not his trust in God, but in man. Wherefore also he is unfruitful, like the wild myrtle-tree.