Boam, who was raised Catholic, used many religious themes and metaphors in his script for the film. In preparing the story, he studied grail literature, but ultimately invented new mythology. He made the grail a symbol for faith. He said, "I guess the major given of faith is that it can't be proved otherwise you don't need faith. So that is why I created the idea that the grail can't be removed (from its hiding place). You can find the grail, but you can't really prove that you found it." When Indiana Jones finally discovers the grail hidden among decoys, its knight guardian tells him that he will die if he drinks from the wrong cup. Boam said that this scene is a metaphor for "the one true God vs. false gods". He worried that the film's religious themes would face criticism from the general audience, as well as religious scholars. He was relieved when the criticism didn't appear, saying, "Nobody working on this movie was a religious scholar ... I was wondering if the numerous allusions to Christ in Indiana Jones were going to put people off. I was afraid the kids in the audience would think it was not a very hip subject matter."