The scene where Emma (Etienne Eckert) hysterically tells Aimee's mother that she's missing was shot in one take by Richard Rossi with a hand-held camera because Eckert had just suffered an accident, injuring her ankle. Rossi cleaned her wounds and blood with hydrogen peroxide and suggested she put her hysteria into the scene. The bandage can be seen on her ankle.
Richard Rossi was offered the lead in a remake of Elmer Gantry (1960) but decided the 1960 film was a classic that should not be remade. Since "Gantry" was inspired by Aimee Semple McPherson, he decided to do a film showing the story of McPherson herself.
Director Richard Rossi chose an actor-friend with long hair and a beard to play Jesus at the end of the film. The actor had been battling a heroin problem, relapsed and never showed up. The Jesus role is uncredited and it's a mystery who played Christ embracing Aimee, but rumors persist that Rossi himself wore the wig and played Christ in the final scene.
The speakeasy where David Hutton gives a sermon and collects money from the prostitutes is actually the 1920s speakeasy where the events occurred; it is located on Hollywood Blvd.