I, for one, don’t have a problem with the book series in of itself. It’s fantasy literature and is, in all reality, pretty well written.
On the other hand, I do have a major problem with it, along with its collateral toys and games, being marketed to young children. (Yes, I have a problem with marketing toy magic wands to children)
If you have children who are old enough and mature enough to recognize that this is fantasy literature, that it is not reality, and that it is a “fun” thing to look at a make-believe world that is not in any way related to reality, then I don’t see the harm in it.
If, on the other hand, your children have such vivid imaginations as to be able to identify with the characters sufficiently to place themselves inside the “Hogwarts” scenario, I think that it is possible for the series to do great harm. This is actually not all that difficult because the series is so well written…it could seem that there is this shadow world among all of us Muggles that we are just to blind to recognize.
Children in the second category then might be drawn to contemplate that there is some reality in the series and would, in turn, be drawn to explore if they could, in fact, find such a reality…and there are plenty of practitioners out there who actually do believe in crystals, who actually do believe in spells, who actually do believe in potions, and would be thrilled to help a bright young mind explore this possibility (just go to the “spirituality” section of any large secular bookstore and you can see plenty of evidence of this).
The problem with the toys, movies, and theme park is if your child is in the second category (very active imagination), the stark visual and aural stimulation given by those experiences could help solidify that “alternate reality” in his or her mind. We, as adults, mostly have our inner child under control so that we recognize it to be a fantasy and not reality, so it’s not that big a deal to us…just good entertainment.
I guess my point is that I don’t think the books, the movies, or this park would be sinful in of themselves. But whether they are appropriate would be up to how well grounded your children are in reality. And only you will know that for yourself. If they are well grounded in reality, then it would, in all likelihood, be a really fun time. But if they tend to fantasize excessively, playing roles where they are the “hero” of a book or cartoon or movie, you might want to hold off for a couple of years until they grow out of it. Because this fantasy, if internalized, has a whole lot of bad actors out there who would love to evangelize your kids.
Think about it: if your kids loved Star Trek, role played it, believed it as an alternate possibility for reality, and really internalized that fantasy, they might explore the possibilities as they grow up. OK, so that results in them learning physics and engineering and might result in them developing a warp drive (yes there have been actual scholarly papers written about warp drive, believe it or not). If your kids love Harry Potter enough to internalize it…
Bottom line is that I’m not saying don’t ever do any Harry Potter with your kids. But make sure they’re old enough first.