The Pharisees and other teachers expected a Messiah to be righteous and obey not just the Law but also their regulations. It happened frequently, and it set up a conflict with Jesus:
Luke 15:1-2 Tax collectors and other notorious sinners often came to listen to Jesus teach. This made the Pharisees and teachers of religious law complain that he was associating with such sinful people—even eating with them!
After explaining how a good shepherd will look for any of his lost sheep, Jesus told them:
Luke 15:7 In the same way, there is more joy in heaven over one lost sinner who repents and returns to God than over ninety-nine others who are righteous and haven’t strayed away!