The story of the lost sheep is the first of three stories Jesus tells in Luke 15 that are meant to illustrate God's love and some things about how it works in our lives. All three revolve around something or someone that's lost being found or returning.
Jesus tells the stories when a crowd of riff-raff gathers as he teaches, drawing disapproval from the religious leadership who are also present. "Which of you," he begins, "having a hundred sheep and finding one missing, would not go out and look for it and rejoice when you found it? There is more joy in heaven over one lost sinner who repents than over 99 who need no repentance." I don't know what the first-century Aramaic equivalent of air quotes would have been, but I'll bet you Jesus used them to set off the "need no repentance" in that sentence.
The story has a surface meaning that's hard to miss. Jesus wants to reach out to the folks who need to hear him -- tax collectors and sinners. Just like the sick need a doctor more than the well do, and the sheep wandering around lost needs the shepherd more than the sheep safely in the pen do, the sinners need God more than the righteous do. Of course, the perceptive among us realize we're all lost sheep at one point or another in our lives. We all stray, turning, as Isaiah says, to our own way rather than following God's path for our lives.
But there are some aspects of the story that its original listeners would have understood that we miss unless we explore its context. First-century Judea is not twenty-first century anywhere. The shepherd goes to search the wilderness for his lost sheep, and that's not just a stroll through the hills. One of the reasons he has to find it as soon as possible is because there are a lot of things that live in the hills that would looove to find fresh mutton on the menu. And that's risky, because even though they've ordered mutton they're willing to sample the slow, two-legged buffet as well.
For another, we tend to just think of the number of sheep involved as a convenient round number to use. Jesus' stated meaning makes just as much sense if the shepherd in his story has 97 sheep or 103 sheep. But we overlook the reality that a hundred sheep represented significant wealth in Jesus day. The image might be enough to bring the kind of dreams we reserve for "what-ifs" about our Powerball ticket having the winning numbers.
If Jesus were to tell this story today, he might say, "Which of you, having a billion dollars and finding your checkbook balance shows a thousand-dollar error, would not spend all night balancing and re-balancing it until you found the mistake, and finding it call all your friends and say, 'Rejoice with me, for I have found the thousand dollars that I lost!'"
Who would do that? Would you? I probably wouldn't. I might check the figures once or twice, but the reality is that if I have to live on $999,999,000 instead of $1,000,000,000, I'll likely be OK. Donald Trump probably spends a thousand dollars a month on his hair (and it's not enough). At that level of wealth, amounts as small as a thousand dollars aren't worth the effort. And for a shepherd with a hundred sheep, the idea of risking his life for one that wandered off isn't worth the effort. He still has 99 rams and ewes, so with some soft lights and the right music he's just a few months away from having a hundred sheep again -- probably more.
But, Jesus says, see what kind of a shepherd God is? He won't cut his losses. He'll do everything he can to find the sheep than wandered away and carry it home himself and rejoice when it's back with the flock. We know that Jesus even called himself the good shepherd, recalling the imagery Ezekiel used when he described why the people had strayed away from their devotion to him.
And this is a deeper message in the story, one that we need to hear just as much if not more than the one on the surface. When it comes to us, his creation, God does not cut his losses. He will take any risk and go to great lengths to bring back even one of his lost sheep. Though he had already gained everyone in the world but me, still he would not stop until he had retrieved me as well.