Mark 1:40-42
40 A man with leprosy came to him and begged him on his knees, "If you are willing, you can make me clean."
41 Filled with compassion, Jesus reached out his hand and touched the man. "I am willing," he said. "Be clean!"
42 Immediately the leprosy left him and he was cured.

Leprosy vividly illustrates sin and it fruits. The disease's effects on the body demonstrate the effects of sin on the mind. Leprosy represents God's view of sin, as detestable, deforming, and unclean. Both leprosy and sin begin small then grow relentlessly until they infect the whole person. Luke the physician, in describing the man as "full" of the dreadful disease (Luke 5:12), implies that he was about to die. In this advanced stage of leprosy, he was living apart from other people. According to Leviticus 13:45, he had to wear a cloth over his mouth and cry, "Unclean, unclean."

Imagine giving a shake hand to your garbage man!! How much more a full-blown leper? The puss, the falling limbs, the stink, the look in his eyes. It is not easy for us to touch or to give a back rub. A touch from Jesus could take away all the rots in his body. Indeed a mighty miracle!

In this situation, as in others, Jesus performs a miracle in which there can be no doubt that God alone healed him. God's healing power is most obviously seen when he does mighty miracles in "hopeless" situations. He may simply be letting the situation progress so that we have no doubt about who has come to our aid and whose power solved the crisis. In persevering, we grow spiritually, and he receives greater glory.