Jesus Himself had linked sickness with sin. But here, Jesus said this blindness was not caused by this man's or his parents' sins.
This has led many people to interpret the rest of this verse as saying that God made this man blind just so that He could heal him and be glorified. From this thinking, many teachings have risen about how sickness and other problems in our lives are actually blessings from God, intended to bring glory to God and correction to us. This reasoning does not line up with the other truths of God's Word.
It was not God who made this beggar blind. This man was not born blind because of any one person's sins but because sin in general had corrupted the perfect balance that God had created in nature. Some physical problems happen, not as a direct result of an individual's sins but as an indirect result of sin in general.
Deuteronomy 28 settles forever the question of whether sickness, poverty, and oppression are really blessings in disguise. God says that sickness and poverty are curses - not blessings from God. Christ redeemed us from these curses of the law so that now the blessings may come upon us through Him (Galatians 3:13). God's curses have been placed on Jesus and removed from those who accept Jesus' sacrifice. We are blessed!