Laurence Jones from Grace Fellowship spoke on John 9 concerning the miracle of the man born blind receiving his sight. He spoke on the blindness of unbelief in the light of the Light of the World.
Faith is not a leap into the dark but a step into the light whereas unbelief is darkness, irrational, blindness, prejudiced and miss focused. It cannot see the good that is done and is perversion. Miracles won't help, it's not a problem with the evidence but the will of man that it in bondage. Man is not neutral and his will is not free, he needs a miracle of God's grace to save him. Those who claim to see already don't realise their blindness and their need of Jesus Christ. "Jesus said to them "If you were blind you would have no sin; but now you say "we see." Therefore your sin remains" John 9 v 41