Twenty years ago, Pastor Paul's church was nothing more than a modest storefront. Now he presides over a congregation of thousands, with classrooms for Sunday School, a coffee shop in the lobby, and a baptismal font as big as a swimming pool. Today should be a day of celebration. But Paul is about to preach a sermon that will shake the foundations of his church's belief. A big-little play about faith in America—and the trouble with changing your mind.