Hilary of Poitiers
Catena Aurea · Johannesevangelium 9
Jesus heard that they had cast him out; and when he had found him, he said unto him, Dost thou believe on the Son of God? He answered and said, Who is he, Lord, that I might believe on him? And Jesus said unto him, Thou hast both seen him, and it is he that talketh with thee. And he said, Lord, I believe. And he worshipped him. And Jesus said, For judgment I am come into this world, that they which see not might see; and that they which see might be made blind. And some of the Pharisees which were with him heard these words, and said unto him, Are we blind also? Jesus said unto them, If ye were blind, ye should have no sin: but now ye say, We see: therefore your sin remaineth.
(vi. de Trin. circa fin.) If any mere confession whatsoever of Christ were the perfection of faith, it would have been said, Dost thou believe in Christ? But inasmuch as all heretics would have had this name in their mouths, confessing Christ, and yet denying the Son, that which is true of Christ alone, is required of our faith, viz. that we should believe in the Son of God. But what availeth it to believe on the Son of God as being a creature, when we are required to have faith in Christ, not as a creature of God, but as the Son of God.