Actually, Christian based magic is very common. Much of the magical Qabalah taught today is modified to have a Christian theme. The Golden Dawn teaches magic with Christianized Qabalah and Egyptian magic. As you study the magical Qabalah you'll find it gives Christanity an entirely different meaning which is probably closer to what the religion was meant to be. It is also much more harmonious and accepting of other religions than what people think. There is no danger in practicing Christian magic. Well, no more than practicing any other form of magic.