What does John 9:8 mean?
Jesus has just given eyesight to a man born blind: a powerful metaphor for how God grants faith and belief to those who would otherwise never have it. This incident included Jesus' explanation that not all suffering is caused by the hurting person's own sin (John 9:1–4). Jesus also breached the Pharisees' traditions by not only healing on the Sabbath (John 9:14), but also by mixing clay (John 9:6): a crime according to their oral laws.When Christ healed the lame man at the Pool of Siloam (John 5:1–9), the subject would have been well-known for his condition. It was not an unknown, possibly staged actor. Here, the same idea applies. This man's lifelong blindness was common knowledge. There is no possibility this was a mere trick. Questions raised about this man's identity are not all expressions of doubt. Most are simply declarations of surprise. The people know exactly who this man is, and precisely what his problem was. For that specific person to suddenly have sight is shocking.
Of course, there will always be hardened cynics (John 9:9). Some in the crowd try to suggest this is not actually the well-known blind beggar, but an uncanny lookalike. Despite the man's own claims, and the witness of the crowd, some chose to reject the evidence of a miracle. This is a common occurrence even today. It demonstrates why the claim, "show me a miracle and I'll believe" is not an honest response to the gospel.