Elmer Gantry is a hard-drinking, fast-talking traveling salesman with a charismatic personality who infuses biblical passages and fervor into his pitches as a way to ease and collect money. He is drawn to the roadshow of Sister Sharon Falconer and is immediately attracted to the saintly revivalist. As the troupe leaves town for Kansas, Gantry sweet talks her naive assistant, Sister Rachel, into telling him information regarding Falconer's past. He uses that information to con his way into Sister Sharon's good graces and joins the troupe preaching "Christ in commerce" and how he is a saved salesman.