How to make this movie more intense

Rating: 9/10 (29 November 1999)

The Exorcist is undoubtedly the scariest movie ever made. To be fair, though, the level of intensity has a strong correlation with your religious beliefs. If you're an atheist, it won't be terribly frightening, but if you know that this stuff is real, then you'll be left shaking.
The movie's plot is a 12 year old girl is possessed by the devil, and her mother enlists the help of a priest to rid her of this evil. If you are aware of the history of demonic posession you will see how accurate this movie is. Notice how Father Karraes struggles with his faith, and how that affects his ability to deal with the devil. Look up Mark chapter 5 in a Bible and make the connections, particularly what the demon would rather have happen to him (them). Brilliant translation, depending on your beliefs. Don't infer too much, though.
The movie draws you in psychologically. Just imagine being in that situation (and the way the film is crafted it's not very hard to imagine), faced with a power you previously did not believe in, while watching your child mutilate herself and utter unspeakable things. Not to mention all the supernatural stuff (shaking bed, wind in closed room, moving furniture, etc.).
To experience this movie best, you should read up on some of the beliefs of the church, instances of possession, and what it all means. Don't pay attention to the gore or special effects -- focus on how your life would be changed if you experienced such an evil, and how you would react to a power that is more real than you could have imagined.