Steve Martin plays the Reverend Jonas Nightingale, a revivalist preacher with a roadshow of gospel music, miracles, and wonders. He's a cynical hustler who nows how to read people and make money off their vulnerabilities. Jane, a savvy but lonely woman, is his business manager. Her technological expertise is essential to Nightingale's ability to work the crowds gathered under the revival tent.
When their bus breaks down in Rustwater, Kansas, the corn-relish capital of America, they learn that the rural community has been hard hit by a drought and unemployment. The sheriff unsuccessfully tries to shut the revival down, seeing it as a flim flam operation that the community cannot afford. Equally distrustful is a local waitress whose disabled brother has already been hurt by an insensitive evangelist.
Nightingale uses every trick in the book to prey upon the hopes and the dreams of the townsfolk. He even rigs up a life-sized statue of Christ so that tears stream down its face. Thousands of outsiders arrive at the tent, eager to experience a miracle.
Screenplay writer Janus Cercone exposes the mixture of credulity and belief characteristic of many who attend revivals. Nightingale is convinced that he can control the spiritual velocities which he sets in motion. A bigger skeptic than the sheriff, imagine this man's astonishment when God has the last laugh. The point of Leap of Faith is well worth pondering miracles cannot be summoned by command; they happen spontaneously, by grace, and often to those who least expect them.