In the study of religion, we use the word magic sparingly because, so often, it is employed as a cheap way of describing faiths whose supernatural forces we simply don’t credit. No, that dance did not make it rain. No, that buried statue in the yard did not help you sell the house. No, that special prayer did not heal your leg. The causality seems simultaneously too direct (this action yields this exact result) and too vague, like you’re pulling on a thread with nothing at the end.
Not to mention that religious people tend to get really pissed off if you refer to their beliefs as 'magic' rather than 'god's power' or 'faith manifest' or something.

