What does John 9:16 mean?
Jesus' miracles are meant to prove that He is the Promised One—the Messiah. In the Old Testament, curing blindness is given as one such sign (Isaiah 29:18; 35:5; 42:7). Jesus has done just that, granting sight to a man who has been blind his entire life (John 9:1–7). Many in the crowd are shocked, even doubting whether or not the now-seeing beggar is the same person (John 9:8–9). Since this event is sensational, and occurred on a Sabbath day (John 9:14), the people bring the man to be interviewed by the Pharisees (John 9:15).In Jesus' day, the Pharisees actually had a very positive reputation. They were extremely moral, living by a strict set of rules which had grown out of their traditions. Those traditions were aimed at "protecting" obedience to the law of Moses. In practice, however, the Pharisees treated those traditions as if they were equal to the actual Word of God. Not only did this result in a cold legalism, it led to the arrogance of an "us-versus-them" version of spirituality.
As a result, even when faced with a miracle, these men define right and wrong, and good and evil, according to whether or not the messenger agrees with their interpretations. Unfortunately, this is not an uncommon problem even today. Many groups choose a particular "pet doctrine," such as a particular day of worship, or a translation of the Bible, and use that as the first test of truth. Those who disagree with that stance are immediately dismissed as sinners, heretics, or false prophets. In effect, this makes that tradition, or doctrine, the real "god" of that sect, blinding them even to miraculous evidence of the truth.