The movie presents fewer than 100 pages of the novel "Elmer Gantry", deleting many characters and fundamentally changing the character and actions of female evangelist Sister Sharon Falconer, as played by Simmons. The character of Sharon Falconer was loosely based on elements in the career of the Canadian-born American radio evangelist Aimee Semple McPherson, who founded the Pentecostal Christian denomination known as the International Church of the Foursquare Gospel in 1927. In addition, a plot point from the end of the novel is incorporated into Gantry's and Lulu Bains's relationship, fundamentally changing the fates of both characters.