João 9
Hilary of Poitiers · Comentário Patrístico (catena)
João 9:35
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.
João 9:35
When the man was already healed and had suffered ejection from the synagogue, the Lord put to him the question, "Do you believe on the Son of God?" This was to save him from the thought that he had lost everything by being excluded from the synagogue. It gave him the certainty that confession of the true faith had restored him to immortality. When the man, his soul still unenlightened, answered, "Who is he, Lord, that I may believe on him?" the Lord's reply was, "You have both seen him, and it is he that speaks with you." For his goal was to remove the ignorance of the man whose sight he had restored and whom he was now enriching with the knowledge of so glorious a faith. Does the Lord demand from this man, as from others who entreated him to heal them, a confession of faith as the price of their recovery? Emphatically not! For the blind man could already see when he was thus addressed. The Lord asked the question in order to receive the answer, "Lord, I believe." The faith that spoke in that answer was to receive not sight but life. — On the Trinity, Book 6.48