http://bible.us/Mark2.13.NLT Then Jesus went out to the lakeshore again and taught the crowds that were coming to him. As he walked along, he saw Levi son of Alphaeus sitting at his tax collector’s booth. “Follow me and be my disciple,” Jesus said to him. So Levi got up and followed him.
Later, Levi invited Jesus and his disciples to his home as dinner guests, along with many tax collectors and other disreputable sinners. (There were many people of this kind among Jesus’ followers.) But when the teachers of religious law who were Pharisees saw him eating with tax collectors and other sinners, they asked his disciples, “Why does he eat with such scum?”
When Jesus heard this, he told them, “Healthy people don’t need a doctor—sick people do. I have come to call not those who think they are righteous, but those who know they are sinners.”