In addition, Normal shepherds would recount their remaining 99 sheep and decide that going after the one lost sheep wouldn’t be worth the trouble. Jesus, However, is a “good shepherd”, therefore he would go out of his way to save one sinner, rather than try to keep the believers he has now safe, because he believes that the believers he has can take care of themselves and their faith. And when he saves, the sinner, he and the kingdom of heaven rejoices more than if he had kept the 99 other strong believers safe.