Jesus heard that they had cast him out; and when he had found him, he said unto him,
Do you believe on the Son of God?
All Commentaries on John 9:35 Go To John 9
Hilary of Poitiers
AD 368
If any mere confession whatsoever of Christ were the perfection of faith, it would have been said, Do you 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 two of Christ alone, is required of our faith, viz. that we should believe in the Son of God. But what avails 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.