is there a devil?

Last night not much on tv, so I watched The Devil's Advocate (one of Pacino's most underappreciated movies), one of my favorite movies. I realized that I love a lot of movies about the devil and the battle between good and evil. The curious thing is i'm, well I don't know what the word is, but lets call it 'undecided'. So if I doubt the existence of one involved supreme power of good then it reasons the same would go for a single force of evil, right? Maybe I just am drawn to the struggle between right and wrong which translates better in stories/movies thru god vs devil? I think my darker side would have been a more destructive force in my life if not for my parents. Who knows? Anyway, there are many great 'devil' movies out there to check out like devil's advocate, 9th gate, devil wears prada-lol, oh god you devil, an incovient truth (gore is devil? lol), etc etc etc....