Many believe it is the most terrifying motion picture of all time, but the author of the novel that inspired The Exorcist insists he never planned to write a horror story. His real goal was to provide readers with a reason to believe in God.

As William Peter Blatty writes in the column at the Fox News link above: “When I first heard, in 1949, of an actual case of demonic possession and an exorcism going on nearby while I was a junior at Georgetown University, I remember thinking, ‘Someday, somebody’s got to write about this, because if an investigation were to prove that possession is real, what a help it would be to the struggling faith of possibly millions, for if there were demons, I reasoned, then why not angels? Why not God?’”

We believe that very idea is the reason why the movie terrifies. Unlike zombies, vampires, ghosts and witches, viewers sense a truth behind the story, a glimpse of hell as it may actually exist.