Augustine of Hippo
Catena Aurea · Johannesevangelium 12
Jesus cried and said, He that believeth on me, believeth not on me, but on him that sent me. And he that seeth me seeth him that sent me. I am come a light into the world, that whosoever believeth on me should not abide in darkness. And if any man hear my words, and believe not, I judge him not: for I came not to judge the world, but to save the world. He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day. For I have not spoken of myself; but the Father which sent me, he gave me a commandment, what I should say, and what I should speak. And I know that His commandment is life everlasting: whatsoever I speak therefore, even as the Father said unto me, so I speak.
(Tr. liv. 4) Whereby it is evident, that He found all in darkness. In which darkness if they wish not to remain, they must believe in the light which is come into the world. He says in one place to His disciples, Ye are the light of the world; but He did not say to them, Ye are come a light into the world, that whosoever believeth on you should not abide in darkness. All saints are lights, but they are so by faith, because they are enlightened by Him, from Whom to withdraw is darkness.