The man that was born blind
The sickness of the man that was born blind, according to John's report, was that the works of God would be manifested in him. That was fully accomplished. The healing of that man is not only a miracle done by the Lord Jesus, but also a metaphor of the spiritual blindness of humans and how it can be healed.
After the Lord healed that man, his vision of the Lord Jesus Christ growed through three steps. At the end of these, the Lord Jesus revealed Himsellf to him.
When the people asked who healed him, he said: "The man that healed me is called Jesus". The man's knowledge is vague and insufficient. The second time he is interrogated by the Pharisees, he replies that Jesus is a "prophet". Here we see that light begins to manifest in him. Sometime later, when the Pharisees urged him further, he become bolder, even to the extreme of telling them: "If He had not come from God, He would not have been able to do anything".
On one hand he was accepting the risk of giving a favorable testimony about Jesus. On the other hand he was emphatically declaring that Jesus came from God. After this testimony the Jews expulsed him from the synagogue.
When Jesus heard that they had barred him from the synagogue, He sought him, found him, and asked him: "Do you believe in the Son of God?" Then Jesus revealed Himself to him.
Here we have some important things to highlight. Firstly, spiritual light, revelation, is gradual. Although the blind man was immediately healed of his blindness, his spiritual knowledge ascended through three steps of increasing light.
Secondly, to receive further light, you have to be consistent with the light you have already received. The man stayed firm in the midst of being abandoned by his parents and by the hostility of the Jews. He was not afraid of their threats. His gratitude and his desire to honor the One that had healed him prevailed more than any other consideration.
Thirdly, the light he progressively received, was literally "pulling" him out of the synagogue. His final discussion was with the Pharisees. It placed him in a totally different group in regards to his interrogators. That is why it must not have surprised him that they expelled him. Jesus was not accepted in the synagogues as the Christ. In that company there was no place for Him.
In the fourth place, Christ revealed Himself to him when he was out of the synagogue. Only outside of that formal and oppressive system, the man was enabled to really know Who Jesus is. Inside the synagogues, only Moses was acknowledged as the prophet ("we are disciples of Moses"). To them, Jesus was nobody. The Lord did not disqualify the synagogoues, although they were an institution outside of the Law. Synagogues did not come from God. They were man's invention and surged during the Babylonian captivity. Nevertheless, the fact that He did not criticize the synagogues did not mean that He backed them up. In the synagogues the Law and the prophets were read--both giving testimony about Him. However, He Himself was not believed in.
Religious systems choke spiritual life and quench spiritual light. Synagogue adherents become defenders of great men of the past, but forget and do not experience true intimacy with the true God.
Honest men love the light. But not everybody is willing to pay the price to obtain the light. That is why the intensity of the light does not increase, and Jesus is not really known, much less experienced.