Harry Potter is a fictional series in which the titular character, having lived with his abusive aunt and uncle since he was a baby, is informed that he is a wizard. Not just a wizard, but "the chosen one", being the only wizard capable of destroying the evil Lord Voldemort. When people hear "wizard", they immediately think of a wand-wielding warlock capable of causing supernatural events with the use of various special words and phrases. And of course, when you read Harry Potter, that's a fairly accurate assessment.
The world of Harry Potter is filled with weird and wonderful things. Things which, in the real world, are actually not possible. There are a host of sentient beings which are neither human nor angel, such as goblins, centaurs, and giants. There are special creatures, such as dragons, thestrals, and unicorns. People can do things such as fly on brooms, or turn animals into water goblets. Pictures live, stair cases move, cars fly, there really is no limit to the imagination of J.K. Rowling.
All of these things, of course, are impossible in the real world. No one believes any of this is actually real. Why, then, do so many Christians act like they believe it is? To many Christians, Harry Potter is an abomination. You're said to be sinning if you read or watch it, and it's supposedly a gateway to other demonic things.
This is problematic, first of all because atheists needed no help in comparing the Bible to Harry Potter. They do this more than enough as it is. It's literally an eye-rolling cliche at this point. So how much more are they going to do it if they think we so firmly believe in Harry Potter that we condemn the enjoyment thereof?
Of course, there is the elephant in the room in that the Bible genuinely does mention things like "dragons" and "unicorns", and yes, it condemns sorcery. But there is actually a distinction.
First, I want to mention a Facebook page by the name of "Word Porn". The word "porn" refers to the gratuitous depiction of sexual activity, but other than the questionable choice of name, "Word Porn" actually has no relationship with the sinful practice of using porn. When I say "porn is wrong", I do not mean "you should not follow the Word Porn page, or share their posts". I'm saying you should not actively seek out sexually explicit material.
With this in mind, we can establish that even words directly related to sin can be used to refer to something that is absolutely not sinful. In the same way, the Bible's references to sorcery refer to something very real, and noticeably distinct from the sorcery in the Harry Potter universe.
The magic in the Harry Potter universe is almost completely imaginary. There are, of course, some overlaps. Malfoy, for example, is able to summon a cobra, just as Pharaoh's magicians were able to turn their staffs into snakes, imitating Moses. Key difference number one here is that in Harry Potter, magic is something a person is born with. In real life, however, there is no way to do real supernatural acts without a supernatural aid, be it a demon, or even God Himself. Therefore, unless God or a demon helped the magicians turn their staffs into snakes, the Egyptian magicians used natural means of trickery to make it appear as though they had matched Moses' sign.
Regarding dragons and unicorns, these are actually translation choices made primarily by the authors of older Bible translations (which is why translations are so often mismatched when it comes to animal names). The so-called "unicorn" is actually the "re'em", and suggestions of its true identity range from the rhino to the aurochs. Similarly, dragons are more than likely dinosaurs and other large reptiles. Over time, the diminishing reality enabled imagination to creep in, as both creatures became embellished.
But this causes a huge problem. When the same word describes two things, one real and one bonkers, one might end up missing the reality, particularly if the imaginary version is so heavily emphasised. What this means is that Christians are actually harming other Christians, too, simply because when they come across modern practitioners of actual magic, they won't know it. You're telling them not to enjoy a fantasy world of fiction, and the result is they are blind to some very real threats.
Ultimately, while I can see the intention behind Christian caution regarding Harry Potter, the moment one knows enough about Harry Potter to realise none of this is real, one should also know it's not sinful, and certainly not worth dividing over. The sorcery described in the Bible is a sin, and Christians should avoid it like the plague, but the sorcery of the Harry Potter world is completely harmless. Any Christian who wants to convince me otherwise may do so by showing me a single boy who is able to walk through train station walls.