It all depends.
For one thing, if it turns out the creator has some spiritualist or religious viewpoint he/she is trying to push, that'll ruin it for me somewhat. That is, it's being "preachy" (think Chronicles of Narnia).
If there's any crypto-Christian stuff in there, it'll lose major points with me for sure. But it all depends on how it's done. For example, I love the Hellraiser series, but it only superficially invokes the Christian mythos. Sure, there's demons, and Hell, but there's no angels, or heaven, and it seems like anybody can be victimized by the demons, whether they believe or not. Also, there are NO priests fighting the demons with crucifixes and stuff (thankfully). I think there may've been more religious overtones in Hellraiser III, but that whole film was so bad I've blocked it out of my memory.
Pretty much anything where Christians are fighting the devil and his forces of evil is really lame. The Omen, Rosemary's Baby...it seems like these should only be scary to Christians.