"As Jesus 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'" (Mk. 2:14-17).

"Levi would have been a Jewish tax official in the service of Herod Antipas. Such officials were detested everywhere and were classed with the vilest of men. The practice of leasing the customs duty of a district at a fixed sum encouraged gross oppression by tax officers anxious to secure as large a profit as possible. When a Jew entered the customs service he was regarded as an outcast from society: he was disqualified as a judge or a witness in a court session, was excommunicated from the synagogue, and, in the eyes of the community, his disgrace extended to his family" (William L Lane NICNT).

Unlike John's Gospel, Mark starts with Jesus preaching: "The time promised by God has come at last! The Kingdom of God is near! Repent of your sins and believe the Good News!" John the Baptist had already called God's people to be baptised confessing and repenting of their sin. Jesus later said to the Pharisees: "Corrupt tax collectors and prostitutes will get into the Kingdom of God before you do. For John the Baptist came and showed you the right way to live, but you didn’t believe him, while tax collectors and prostitutes did. And even when you saw this happening, you refused to believe him and repent of your sins" (Mt. 21:31-32). 

Isn't this brilliantly illustrated by Paul's words: "Don’t you see how wonderfully kind, tolerant, and patient God is with you? Does this mean nothing to you? Can’t you see that his kindness is intended to turn you from your sin [and to lead you to repentance]?" (Rom. 2:4). God's loving kindness is intended to bring sinners to repentance. When we treat the lost with God's loving kindness, acceptance and respect we become His co-workers. Jesus modelled this for us. Mercy triumphs over judgement.