Augustine of Hippo, on 1John 4:2

“By this is the spirit of God known. Every spirit which confesseth that Jesus Christ is come in the flesh, is of God:”

“What is the spirit that is not from God? That "which denieth that Jesus Christ is come in the flesh." And what is the spirit that is from God? That "which confesseth that Jesus Christ is come in the flesh." Who is he that confesseth that Jesus Christ is come in the flesh? Now, brethren, to the mark! let us look to the works, not stop at the noise of the tongue. Let us ask why Christ came in the flesh, so we get at the persons who deny that He is come in the flesh. If thou stop at tongues, why, thou shalt hear many a heresy confessing that Christ is come in the flesh: but the truth convicteth those men. Wherefore came Christ in the flesh? Was He not God? Is it not written of Him, "In the beginning was the Word, and the Word was with God, and the Word was God"? Was it not He that did feed angels, is it not He that doth feed angels? Did He not in such sort come hither, that He departed not thence? Did He not in such sort ascend, that He forsook not us?”

Imported from an open dataset — not yet checked against the printed edition.