This is one of the best sermons my pastor (and husband) has ever preached. And that's saying something.
The passage is the ever-familiar "Prodigal Son" story, but within the context of the culture of the Bible days. But be warned: this is likely to rock your entire thinking on repentance - either theologically or (and) practically. (Set aside an hour if you want it all at once and some time to digest)
P.S. If you want more context (or if the above link didn't get you there) go to www.bygraceonline.org, click "Audio Sermons" on the right, then either by year or passage. This was Luke 15:11-24, given on November 16, 2008. He started chapter 15 on October 9, so there were three other sermons preceding this. And if you like the story of the first son, feel free to listen to the following week (also worth it) when he tackles the older brother.