While observing the Lord Jesus receiving sinners, the pharisees judged from a distance, believing they were superior to the publicans and sinners that were sitting with Jesus. They failed to recognise that they were sinners too.
Tim Lewitt helpfully explains the reason (and the reason not) for His coming, found in Mark 2:14-17
Did you know you’re a sinner?
Did you know you can be saved from you sins?