Tractates on the Gospel of John

² I think that what the Lord says, “I am the light of the world,” is clear to those that have eyes, by which they are made partakers of this light: but they who have not eyes except in the flesh alone, wonder at what is said by the Lord Jesus Christ, “I am the light of the world.” And perhaps there may not be wanting some one too who says with himself: Whether perhaps the Lord Christ is that sun which by its rising and setting causes the day? For there have not been wanting heretics who thought this.

The Manichæans have supposed that the Lord Christ is that sun which is visible to carnal eyes, exposed and public to be seen, not only by men, but by the beasts. But the right faith of the Catholic Church rejects such a fiction, and perceives it to be a devilish doctrine: not only by believing acknowledges it to be such, but in the case of whom it can, proves it even by reasoning. Let us therefore reject this kind of error, which the Holy Church has anathematized from the beginning.

Let us not suppose that the Lord Jesus Christ is this sun which we see rising from the east, setting in the west; to whose course succeeds night, whose rays are obscured by a cloud, which removes from place to place by a set motion: the Lord Christ is not such a thing as this. The Lord Christ is not the sun that was made, but He by whom the sun was made. For “all things were made by Him, and without Him was nothing made.”