The Lord may put us into situations in which we may display His power and His glory. We were created for His glory.
When we walk in Christ, we do not stumble. Jesus is the Light. Only through Him can we know the way. The Pharisees were blind because they walked in darkness.
The presence of light reveals the condition of one's eyes. We cannot know that we are blind if we walk in total darkness. In much the same way, the presence of the Lord reveals the condition of one's soul. We must use the glorious spiritual Light of God to continually check ourselves. In the Light, we can no longer cloak our sin. (John 3:19-21)
"Whereas I was blind, now I see." The blind man's testimony is simple, straightforward, and to the point. There is no embellishment. It gives all the glory and credit to God. His past is irrelevant. No focus is given to how much of a sinner he was. Only that before he walked in spiritual darkness, and now he walks in spiritual light. What a powerful statement. This, truly, is the message.
The Pharisees ask the man repeatedly how it was that he came to see. He tells the Pharisees, "I have told you already, and ye did not hear." They did not hear because, though the spiritual light had been shined onto them, they remained blind to the truth. The condition of their souls had been revealed.
"Dost thou believe on the Son of God?" This, ultimately, is the question. It is the question that leads us to salvation in the grace of the Lord. The man's answer points to his eagerness to seek God: "Who is he, Lord, that I might believe on him?" We must seek God with this same eagerness. "Lord, I believe."