The parable of the Lost Sheep illustrates the joy in heaven over a sinner that repents. In this parable, Jesus tells the story of a shepherd who leaves his flock of 99 sheep to search for one that has gone astray. When he finds the lost sheep, he rejoices and calls his friends and neighbors to celebrate with him.
Jesus uses this parable to illustrate how much God loves each and every one of us, and how He rejoices when a sinner repents and returns to Him. It shows that no matter how lost we may feel, God is always seeking us out and welcoming us back into His loving arms. The parable teaches us that we should always be willing to seek out and help those who have strayed from the path of righteousness, just as the shepherd did for his lost sheep.