Sample of this nice, sensible post over at Tropic Temper:
(Now let's get one thing straight. People may play at witchcraft, and believe in witchcraft. But it doesn't actually work. It's on the same level as seeing fairies at the bottom of the garden. If you believe in witchcraft, then I have news for you - you are gullible and apparently incapable of applying critical thinking to what you are told. My advice? Go read Carl Sagan's "The Demon-haunted World" and then come back and argue with me if you still believe in mumbo-jumbo.
I am fond of saying that I write fantasy: I don't believe in it. It's called entertainment, yanno?)
There's also some discussion in the comments, e.g. about stuff like "The Secret".