Do a search in google images of leprosy. Instantly, we faced with a visual disease. That sickness (not the patient) is ugly, unclean, repulsive, and unwelcome. Yack! Leprosy is contagious. We are all stained with this disease. Most of us can not see it but God can. Sin is inward leprosy. Sin is ugly, unclean, repulsive, and unwelcome. Sin is contagious. Psalm 1. Yet the Bible record both in the Old and New Testament that God never disregard those who had leprosy. Jesus touched the leprous to heal them. Must He touch them? No, but He chose to demonstrate to us how much He loved. Later Jesus died for sinners. Note that in Leviticus 13:13, a person who is covered fully with leprosy was to be pronounced clean by the priest. If we think we have sinned partially we can be dead wrong. God is delivering us from ourselves. Only a fully sinful man can understand how much he can be fully forgiven.