Luke 15: 1 - 7 (NIV): 1 Now the tax collectors and "sinners" were all gathering around to hear him. 2 But the Pharisees and the teachers of the law muttered, "This man welcomes sinners and eats with them." 3 Then Jesus told them this parable: 4 "Suppose one of you has a hundred sheep and loses one of them. Does he not leave the ninety-nine in the open country and go after the lost sheep until he finds it? 5 And when he finds it, he joyfully puts it on his shoulders 6 and goes home. Then he calls his friends and neighbors together and says, 'Rejoice with me; I have found my lost sheep.'7 I tell you that in the same way there will be more rejoicing in heaven over one sinner who repents than over ninety-nine righteous persons who do not need to repent.
This story tells us a lot about God's character. He loves everyone. He isn't judgmental, but instead, goes after those who are lost from him or who have strayed from him. He, like any good father or shepherd, wants us to be found and safe. The Pharisees thought Jesus should shun sinners if he really was the Christ, but they were wrong. Jesus said he came to save that which was lost.
He told this parable to show how God feels about sinners and lost people. A shepherd would actively seek after one lost sheep. The shepherd, Jesus said, would in fact leave the ninety-nine and search for the lost one. That's God's attitude -- he doesn't want to lose even one person. And it thrills his heart when a lost person comes to him and is saved. God's heart is for evangelism and always has been. Ours should be too. We should be concerned about people all around us who have never found Christ, or who have strayed away and need to be found again.
Jesus wasn't tempted by the "sinners" who came to hear him, instead he had compassion on them. He loved them just as they were, but he loved them too much to let them stay that way. He wasn't celebrating their sinfulness, but was calling them to repentance. That's what pleases God and it should please us too.