My guest is Richard Beck. His new book is Trains, Jesus, and Murder: The Gospel according to Johnny Cash. "Saints and sinners, all jumbled up together." That's the genius of Johnny Cash, and that's what the gospel is ultimately all about.Johnny Cash sang about and for people on the margins. He famously played concerts in prisons, where he sang both murder ballads and gospel tunes in the same set. It's this juxtaposition between light and dark, writes Richard Beck, that makes Cash one of the most authentic theologians in memory. In Trains, Jesus, and Murder, Beck explores the theology of Johnny Cash by investigating a dozen of Cash's songs. In reflecting on Cash's lyrics, and the passion with which he sang them, we gain a deeper understanding of the enduring faith of the Man in Black.