What did the Sheep do to repent?
Which one of you, having a hundred sheep and losing one of them does not leave the ninety-nine in the wilderness and go after the one that is lost until he finds it? And when he has found it, he lays it on his shoulders. And when he comes home, he calls together his friends and neighbors, saying to them, "Rejoice with me, for I have found my sheep that was lost." Just so I tell you, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance.
Jesus says, "...there will be more joy in heaven over one sinner who repents..." Clearly in this parable the sheep (as does "the coin" in the lost coin parable, and "the sons" in the prodigal parable) represents the sinner. This begs the question, "What does the sheep do ('the coin do'; 'the sons do') that resembles repentance?"
In the Middle East, to find and to restore a lost sheep often takes two-to-three days. When a sheep realizes that it is lost, it freezes and can only bleat (cry out). Even when the sheep hears the voice of his shepherd, it can’t move because it’s too terrified. This is why the shepherd must carry the sheep back to the fold. In the Middle East, with its rugged terrain, carrying a sheep is a difficult and dangerous task. Shepherds—hired hands—would be obligated to find the sheep. But because the effort of restoring the sheep was so difficult, they would often wish the sheep dead. However, with the Good Shepherd, He finds and restores each of us with joy.
To grasp its full meaning, we need to look at all three of these inter-related parables (the lost sheep, the lost coin, and the lost sons). In them, Jesus declares that he came to earth to find and restore his people. And through these parables, Jesus is redefining "repentance" to mean “accepting being found.” Jesus shows that its his responsibility is to find and restore. It's our responsibility—our repentance—to “accept being found.”Lost Sons (Prodigal) Parable