The Believers

The film is based on the 1982 novel The Religion by Nicholas Conde (a pseudonym for Robert Stuart Nathan), which director John Schlesinger wanted to adapt because he found it very cinematic.

Schlesinger and screenwriter Mark Frost spent a year adapting the novel, enlisting the book's authors to help research Santería, a religion referred to by its practitioners as 'the religion'.

Because Santería is a closely guarded religion, the filmmakers relied on actress Carla Pinza, who plays housekeeper Carmen Ruiz, as a technical advisor since she was an initiated priestess of Santería.

Schlesinger deliberately chose to depict Santería as a benevolent force in the film, while portraying Brujería (black magic) as the story's true antagonistic force, in order to avoid misrepresenting the religion.

Filming took place primarily in Toronto, with some exterior scenes shot in New York City, from June 5 to September 28, 1986.

The film has been cited as having influenced the real-life cult led by Adolfo Constanzo and supported by Sara Aldrete in Matamoros, Mexico, which was based on Palo Mayombe, an Afro-Cuban religion similar to Santería.

Critic Roger Ebert gave the film one and a half stars out of four, criticizing it for depicting Caribbean religions only through negative stereotypes like blank-eyed cultists and bloodthirsty rituals without ever explaining their meaning.

Scholar Barna William Donovan compared the film's demon-worshiping, child-abducting cult to the villains of Indiana Jones and the Temple of Doom, and noted its similarities to Angel Heart as one of the few notable 1980s films about Devil worship.