Luke 15:3-7

So He told them this parable: “What man among you, if he has a hundred sheep and loses one of them, does not leave the ninety-nine in the wilderness and go after the one which is lost, [searching] until he finds it? [Matt 18:12-14] And when he has found it, he lays it on his shoulders, rejoicing. And when he gets home, he calls together his friends and his neighbors, saying to them, ‘Rejoice with me, because I have found my lost sheep!’ I tell you, in the same way there will be more joy in heaven over one sinner who repents than over ninety-nine righteous people who have no need of repentance.