In shining forth the light in John 9, the healing of the blind man magnificently illustrates spiritual salvation since there is a link between this man’s blindness from birth and man’s spiritual state from birth.
The Apostle Paul writes in Rom. 5 that when God’s love through Christ saves, it happens while we were enemies, helpless and sinners. This is also described by Paul in Eph. 4, which states that unbelievers have futile and darkened minds due to their hardness of heart. This is why Paul’s ministry is delineated by Jesus Chris in his commissioning recounted in Acts 26:17…I am sending you, 18 to open their eyes so that they may turn from darkness to light and from the dominion of Satan to God…
This is what God must do in the spiritual realm to save a sinner and it’s signified by Christ’s healing of this blind man. This man could do nothing about his blindness and thus the power of Christ is demonstrated on the helpless. So after all the contention and opposition in ch.8 with the crowd, the religious leaders and the Pharisees, Jesus comes across a blind man who doesn’t even say anything, and is just sitting there unable to do anything, yet this man receives the benefits of the Light of the world and it is clear by the end of this account that he is not only saved from his physical blindness, but also his spiritual blindness. Praise be to God!