Throughout his conquests, Alexander the Great read the Iliad, a book that kindles martial zeal. He often placed his copy, annotated by Aristotle, under his pillow at night alongside his dagger. It's not stretching it to say this one story's effect on Alexander may have changed the course of history.

I confess I had been preaching for years before I realized well-told stories wielded this kind of power, that they could actually change people's lives. I happened onto that realization the hard way. My college degree was in accounting, and I've always felt at home with facts, analysis, and principles-the abstract and conceptual. I would have been embarrassed to simply tell a Bible story in a sermon; that was for children. I thought adults needed a quick summary of the story followed by cogent lessons from it.

But then I became pastor of an inner-city church in Chicago. I began to notice my sermons had less impact than in my previous location, a college town. I wasn't shirking on preparation. ...