The Homilies of St. John Chrysostom on the Gospel According to St. John
And as Jesus passed by, He saw a man which was blind from his birth. And His disciples asked Him, saying, Master, who did sin, this man, or his parents, that he was born blind? Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him. (John 9:1-3)
Lo, here again is another difficulty, if without this man's punishment, it was not possible that the glory of God should be shown. Certainly it is not said that it was impossible, for it was possible, but, "that it might be manifested even in this man." "What," saith some one, "did he suffer wrong for the glory of God?" What wrong, tell me? For what if God had never willed to produce him at all? But I assert that he even received benefit from his blindness: since he recovered the sight of the eyes within. What were the Jews profited by their eyes? They incurred the heavier punishment, being blinded even while they saw. And what injury had this man by his blindness? For by means of it he recovered sight. As then the evils of the present life are not evils, so neither are the good things good; sin alone is an evil, but blindness is not an evil. And He who had brought this man from not being into being, had also power to leave him as he was.