Anyone familiar with the Four Gospels notices that the first three: Matthew, Mark, and Luke, look more-or-less the same in their general outline and flow of narrative, leading Biblical scholars to call them the Synoptic Gospels, that is, they "look together" at the life of Christ.
Use of the term "synoptic" also serves to emphasize the uniqueness of the Gospel according to John which very differently portrays the ministry of Christ. John is called "the Theologian" in the Orthodox Church because his choice of events and language describing the ministry of the Savior expounds certain key truths of the Kingdom of God with a depth not expressed in the other three Gospels.
The unique account of the Man Blind from Birth – John 9 – is a prime example of the theology of the Gospel.
The key truths expressed are: distinction between physical and spiritual day/light and night/darkness; the connection, or lack thereof, between sin and its effects; the authority of doctrine/opinion related to actual works/activities; and indications whereby Jesus is recognized through faith as the Son of God in the flesh.
These truths were previously introduced in the Gospel of John, but like an ever-tightening spiral, they become clearer as we re-visit and draw closer to them in their repetition. As in this episode especially, the truth of Christ becomes more and more apparent as the opponents of Christ attempt more and more to suppress it, so that the nature of true blindness (inability to see Jesus as God) becomes unmistakable.
Seeing a man born blind, Jesus' disciples immediately link the affliction to sin. They ask Christ, "Rabbi, who sinned, this man or his parents, that he was born blind?" (John 9:2). Jesus answered, "Neither this man nor his parents sinned, but that the works of God should be revealed in him. I must work the works of Him who sent Me while it is day; the night is coming when no one can work. As long as I am in the world, I am the light of the world" (John 9:3-5). Here Jesus repeats something He said earlier: "I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life" (John 8:12).
Blindness is the inability to see light. We must be able to see the light to follow the light and perform works in the light. The man is not guilty before God for being physically blind. The works of God we must be able to see pertain not merely to physical, material well-being, but to what Christ is doing to reunite us with God – "For as the Father raises the dead and gives life to them, even so the Son gives life to whom He will" (Jn. 5:21); "This is the work of God, that you believe in Him who He sent" (Jn. 6:29). Guilt, the liability to punishment for refusing to acknowledge Jesus as Lord and Savior, results from the willful blindness displayed by the Pharisees who follow themselves rather than walk in the light of God's will.
Rather than curing the man's physical blindness with a word, Jesus submits the man to a process: anointing his eyes with clay and His saliva (purposely done on the Sabbath day), and telling him to wash his eyes with water from the pool of Siloam (the man then has to find his way from the temple in the northern part of Jerusalem to the pool in the southern part). Having accomplished all this, the man came back to the temple being able to see physically. As the ensuing interrogation of the man demonstrates, Christ prescribed this process of healing as an irrefutable fact of His power to save.
Finally the man boldly addresses the religious leaders. "Why, this is a marvelous thing, that you do not know where He is from; yet He has opened my eyes! Now we know that God does not hear sinners; but if anyone is a worshiper of God and does His will, He hears him. Since the world began it has been unheard of that anyone opened the eyes of one who was born blind. If this Man were not from God, He could do nothing" (John 9:30-33). The conclusion is obvious to anyone who has spiritual eyes to see, which is exactly the point of this episode.
In His Sermon on the Mount, our Lord spoke these words: "The lamp of the body is the eye. If therefore your eye is good, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If therefore the light that is in you is darkness, how great is that darkness!" (Matt. 6:22-23).
The Pharisees in John 9 illustrate this truth precisely; they said to Jesus, "Are we blind also?" Jesus said to them, "If you were blind, you would have no sin; but now you say, 'We see.' Therefore your sin remains" (John 9:40-41).
Not only have we been illumined by the light of Christ, but we have been given eyes to see Him. Our eyesight is the spiritual perception of Christ, that He is the Son of God, the Savior. This is the true sight overcoming the most devastating type of blindness, the inability to know the true God and Jesus Christ because of pride and unbelief. Jesus performs what is physically impossible (healing the man born blind) giving us the possibility of everlasting life in the Kingdom of His glory through knowledge of Himself.