Over at the Modern Reformation website, a very helpful article is posted by Dr. Donald Williams, Director of the School of Arts and Sciences and Professor of English at Toccoa Falls College, in which Dr. Williams gives his reflections on the literary and philosophical basis of the now complete Harry Potter series of novels and how they intersect with the biblical teachings that erect the proper boundaries between good and bad fantasy. It’s the kind of intelligent analysis that could do the hearts and minds of fantasy-spooked fundamentalists and evangelicals a great deal of good.
How is it biblically justifiable to portray characters who use magic?
Do fantasy stories ever convey a moral or point which can benefit Christian readers, or should we focus on, and boycott, externals?
How did Harry Potter author, J. K. Rowling, do in keeping within the bounds of biblically-regulated fantasy?
Questions like these are at least indirectly addressed in Dr. Williams’ essay.
The Misadventures of Captain Headknowledge 
I believe there are two sides to this coin, one good, the other bad. Certainly the Christian theme of good triumphing over evil is present in her work. Yet the genre she has chosen borders on unbiblical practices such as witchcraft, sorcery, etc. which the Scriptures clearly prohibit.
David McCrory
The Reformed Puritan
Indeed, Dr. Williams’ essay certainly makes clear that Rowlings’ portrayal of witches in a good light, rather than the imaginary form of good wizards and bad witches (after the tradition of Lewis and Tolkien), but what I find refreshing is the example he provides of a well-thought out critique of fantasy, rather than the general suspicion that many, especially of those in proximity to me, have about fantasy. I’m all for discernment, but I have trouble with legalistic abstinence borne of ignorance of the benefits of the genre.
Oops! I left out a clause!
Let me try that again:
“Rowlings’ portrayal of witches in a good light . . . [falls short of the ideal for good fantasy], but what I find refreshing . . . “
There, hope that helps!