Fantasy is a lens which sharpens and clarifies the sliver of reality viewed through it; magic is one of the tools used to accomplish this. It's a powerful tool and often it is a threatening one, because there is the propensity to react against something that affects you deeply.
Sufficiently advanced magic takes on a reality all of its own and begins to be something believed in on its own terms, with something approaching religious faith. This is possibly the reason why more fundamental Christians feel so violently threatened by such things as the magic in Harry Potter; they confuse a powerful system of magic being used to shape a fictional story and certain aspects of the reality in which it is based with a potential rival to their own creed and dogma and set of beliefs.
Thus magic gets a reputation because it's batting against an already established system which is entrenched, and very much opposed to the things that the new fantasy might be bringing in with it. If any sufficiently advanced technology is indistinguishable from magic, as Arthur Clarke said, then it is also possible that any sufficiently advanced magic is indistinguishable from a religion.
If anything that is beyond our comprehension or ability to explain away by empirical means may be tagged with the word 'magic,' then the Christian mythos starts to drip with the thing – what are miracles if not magic? Changing water into wine? Walking on water? Resurrection, for that matter…? But over the course of two thousand years the magic has hardened into a cracked outer shell of dogma. It is no longer the original magic but the recasting of that magic into something useful and controllable by a series of human interpreters to support their own thesis and grip on power.
There is real magic in belief. Sometimes wishing for something hard enough makes it come true because the sheer power of the act of visualization means that you are working for the manifestation of that thing in your life.
Richard Bach's "Illusions: the adventures of a reluctant Messiah" encapsulates this precisely. Specifically, I am thinking about the blue feather incident, where the reluctant Messiah of the title instructs our POV character, his equally reluctant disciple, on the principles of visualization. Visualize something, the Messiah says, and it will manifest in your life. All right, says the disciple, a blue feather. The Messiah raises an eyebrow but goes, okay, blue feather. CONCENTRATE on it.
Next thing, they're passing a dairy delivery truck and our disciple's eyes go wide. Hey, LOOK, he says, and sure enough, on the side of the truck it says BLUE FEATHER DAIRIES.
This is where it gets interesting.
The disciple says that he expected a "real" blue feather. Yes, says the Messiah, but how did you visualize this when you invited it into your life? Were you holding it in your hand or was it just, like, floating disembodied in space?… Floating, the disciple admits. Well, the Messiah explains, that accounts for it. You didn't personalize the magic and all you did was manifest a generic iteration of the item that you were seeking, not the thing itself in your possession.
Oooooh. It's MAGIC. It's real magic because this is delivered utterly matter-of-factly, as though it were common knowledge, as though anybody could do it.
But this is where the organized and dogmatic faith departs from the pure unfettered faith of a child not yet trained to obey all the rules. The original miracles are crusted over by the barnacles of creed, words that are repeated verbatim every Sunday to the point of becoming invisible, and completely detached from the things that they may actually mean.
Are the "body of Christ" and "blood of Christ" just representations of the things they purport to be or are they MAGICALLY -- and I use the word advisedly -- transformed into the real thing when the priest intones the words above the plate and the chalice? Magic is rich and powerful stuff. Powerful enough to make the faithful, who would otherwise recoil at the idea of eating human flesh or drinking human blood, accept even the most potent of the interpretations of those words when they are uttered by a consecrated being over a consecrated thing and freely partake of it despite the implications and moral and ethical contradictions inherent in what they believe they are consuming.
True magic lies in weaving together something that is impossible with something that is yearning for the impossible in such a way that the impossible thing becomes not just possible but inevitable.
This is what writers do every day.
What is it that makes magic come alive for the reader? Is it that the writer must believe in it first, and to what degree should that belief be taken – philosophical, empirical, dogmatic? What is it about magic that pulls in the human mind? What are the riptides and the undertows of that wine-dark sea in which we all like to occasionally drown?
What makes magic … for YOU?…