Luke 15:1-7 (NIV)
Now the tax collectors and sinners were all gathering around to hear Jesus. But the Pharisees and the teachers of the law muttered, “This man welcomes sinners and eats with them.”
Then Jesus told them this parable: “Suppose one of you has a hundred sheep and loses one of them. Doesn’t he leave the ninety-nine in the open country and go after the lost sheep until he finds it? 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.’ 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.
Matthew 18:10-14 (NIV)
“See that you do not despise one of these little ones. For I tell you that their angels in heaven always see the face of my Father in heaven.
“What do you think? If a man owns a hundred sheep, and one of them wanders away, will he not leave the ninety-nine on the hills and go to look for the one that wandered off? And if he finds it, truly I tell you, he is happier about that one sheep than about the ninety-nine that did not wander off. In the same way your Father in heaven is not willing that any of these little ones should perish.