The story of the prodigal son (Luke 15) is often used by preachers to proclaim the Gospel. Doubtless, the salvation message is there—as we see the Father and the angels rejoicing over the lost who are found. But is that its main purpose?
The answer is NO! Let’s look at its context.
In v. 1 we see the religious leaders complaining about Christ having to do with sinners. Then in verse two, we read
So, He told them this parable . . .
The parable was given not primarily for evangelistic purposes, but to show that Heaven rejoiced over Christ bringing the lost to Himself—in contrast to the self-righteous attitudes of those leaders toward such people.
Moreover, note that there is only one parable—not three: “this parable.”
It has three parts.
The shepherd lost a sheep, and when he finds it, he gathers other shepherds and they all REJOICE that it has been found. Same with the woman finding her lost coin—she gathers her female friends (the original makes clear) and they have a hen party! They too rejoice. So, too, it is with the father—he rejoices. But the elder brother (who represents the Pharisees) grouses instead. He is out of sync with the others (and even with the angels!).
Thus, the parable should be used to show how God and all heaven is pleased with that evangelism among unlovely persons which redeems them—instead of how it is so often used.