The targets of this story are not "wayward sinners" but religious people who do everything the Bible requires. Jesus is pleading not so much with immoral outsiders as with moral insiders. H wants to show them their blindness, narrowness, and self righteousness, and how these things are destroying both their own souls and the lives of the people around them.
Timothy J. Keller, The Prodigal God: Recovering the Heart of the Christian Faith
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