Repentance.

After this he went out and saw a tax collector named Levi, sitting at the tax booth. And he said to him, “Follow me.” And leaving everything, he rose and followed him.
And Levi made him a great feast in his house, and there was a large company of tax collectors and others reclining at table with them. And the Pharisees and their scribes grumbled at his disciples, saying, “Why do you eat and drink with tax collectors and sinners?” And Jesus answered them, “Those who are well have no need of a physician, but those who are sick. I have not come to call the righteous but sinners to repentance.” (Luke 5:27-32)