A young man approached me after I'd preached on Mark 8:34 ("If anyone would come after me, let him deny himself and take up his cross and follow me"). I'd quoted Bonhoeffer: "When Jesus calls a man, he bids him come and die." The young man hemmed and hawed, then said plaintively, "I feel I never do enough for God, so a sermon like that is hard for me."

There it was—the theological tension between doing and grace. The tension was clearly expressed in that young disciple's face. I felt the weight, too. Had I somehow turned "deny yourself and take up your cross" into a way to earn salvation? Had I shortchanged grace?

In-your-face, prophetic preaching poses a challenge for gospel preachers. How do you get up and preach, "Repent and sin no more," when the congregation has just sung "Jesus Paid It All"? Prophetic preaching often goes to the dark heart of bad behavior just when our people have gotten used to hearing about ...