Why are some Christians really afraid of the occult?

I have seen that some(not all) Christians are somewhat uncomfortable with the idea of someone who practices,especially if they find out that you do. I just wonder...why such fear?There people(some) from Wicca to Satanism that can be some of the nicest people you can meet.-----Its just a question....an opinion..please try not to get too mad at me for this!!!----