JD Walters at 2009-10-30 07:37:59:
Being a theology/religion student myself, I don't remember being scared stiff (I was 20 when I saw it, though) so much as 'pumped' or 'psyched'. I had never seen the struggle between pure good and pure evil portrayed so compellingly.
There does seem to be a challenge unique to religiously-themed horror, though: how to avoid letting what I call the 'intrinsically compelling' nature of the subject matter make the writer lazy about characterization, plot, dialogue, etc. How many truly great explicitly religious horror films are there, with compelling characters and story as well as serious theology? Um, The Exorcist...On the other hand is everything else, like the lesser "Exorcism of Emily Rose", "The Reaping", etc.