John Calvin on John 9:31-33

31. Now we know that God heareth not sinners. Those who think that the man spoke this, in accordance with the opinion of the people, are mistaken; for the word sinner, in this passage, as in another which lately occurred, means an ungodly and immoral person. It is the uniform doctrine of Scripture, that God does not listen to any but those who call upon him with truth and sincerity. For while faith alone opens the door to us to go to God, it is certain that all wicked men are excluded from approaching to him; and he even declares that he detests their prayers, (Proverbs 28:9,) as he abhors their sacrifices, (Proverbs 15:8.) It is by a special privilege that he invites his children to himself; and it is the Spirit of adoption alone that crieth out in our hearts, Abba, Father, (Romans 8:15; Galatians 4:6.) In short, no man is properly disposed to pray to God, unless his heart be purified by faith. But wicked men profane the sacred name of God by their prayers, and therefore they deserve rather to be punished for this sacrilege, than to obtain any thing for salvation. Accordingly, the blind man does not reason inconclusively, that Christ has come from God, because God lends a favorable ear to his prayers.

John 9:34-41

34. They answered, and said to him, Thou wast altogether born in sins, and dost thou teach us? And they cast him out. 35. Jesus heard that they had cast him out, and having found him, he said to him, Dost thou believe in the Son of God? 36. He answered and said, Who is he, Lord, that I should believe in him? 37. And Jesus said to him, Thou hast both seen him, and it is he who talketh with thee. 38. And he said, Lord, I believe; and he worshipped him. 39. Then Jesus said, For judgment am I come into this world, that they who see not may see, and that they who see may become blind. 40. Some of the Pharisees, who were with him, heard these things, and said to him, And are we blind also? 41. Jesus said to them, If you were blind, you would not have sin; “Vous n’auriez point de peche;” — “you would have no sin.” but now you say, We see: therefore your sin remaineth.