I have mixed opinions when it comes to weird stuff. My basic attitude is that I neither strongly believe or disbelieve, because most odd things can generally be explained. I've seen and heard some weird stuff (but I've also been heavily medicated for most of my life, one way or another, due to brain damage) but nothing that can't otherwise be explained. As a general rule I figure if there is anything supernatural out there kicking around on the mortal plane, it's not generally a big enough deal to worry about, it's not like you see people getting killed or disappearing under weird, supernatural, circumstances left and right. When things like that DO happen it's usually done by some perfectly mortal guy who believes weird stuff, than by some supernatural entity. What's more having read a lot of paranormal stuff, ghost stories, etc.. being in a hotbed of such tales down here in New England, and as an extension of my interest in horror, it's noteworthy that as a general rule even if true the supernatural doesn't actually kill anyone. For the most part stories like this involve "disappearances" at the worst which also happen under ambigious circumstances and the more evidence there is that something truly messed up is going on (the hardest to disprove cases) the less lethal it's supposed to be. The alleged "Bell Witch Haunting" is apparently one of the few cases where an "accepted" (by experts) ghost has actually killed someone as opposed to just generally being annoying. Simply put the real alleged "supernatural activity" tends to be a lot more mellow than horror movies, which tend to ham it up, even when dealing with "true stories".
*THAT* said the supernatural is legally accepted to exist, which is something a lot of people don't realize. It's actually fairly subtle though, and comes up indirectly in things like real estate law where most states require realtors to tell home owners if a house has a history, largely due to reported incidents going back decades, if not centuries, of people being harassed by spirits in a house. As a result the old horror movie clique of "family gets deal on house, and moves in, not knowing it was cheap because of it's history of odd occurences and murders" doesn't generally happen. Of course at the same time when houses with histories are investigated by "professionals" for TV or whatever with the permission of the realtors/owners they generally don't find anything you know the whole "wooo, we found odd cold spots" and the like... so as I said, you can't explain it, but it hardly tends to be exciting. Personally I'd actually think in temperate areas ghostly cold spots would be a selling point to save on air conditioning bills.
When it comes to possession, I've never run into anything that sold me on that, even as a Christian. Of course I am not a deeply spiritual Christian when you get down to it. As a general rule, I tend to be fairly open minded on that one when it comes to the bigger churches and Christian religions like the Catholics because they tend to be fairly careful in most cases. The Catholics in particular tend to be highly skeptical of flashy events, and "miracles", flashy or otherwise, and heavily investigate everything and anything they get involved in. They generally do not go running around declaring possessions, miracles, etc... left and right. The way I see things if you can convince someone from a legitimate organization that there is a possession going on, there might be something there, either that or you did such a bloody good job intentionally faking it, that your getting what you see out for. The way I see it is that if some kid starts spouting in dead languages, saying things they couldn't possibly know, and moonwalking backwards up walls in front of witnesses to get action taken, I can't blame action for being taken. As I said if it's not real and you teach your kid ancient launguages, and enough parkour to fake it, or managed to get a conspiracy of fake witnesses, because you really want an exorcism under false pretenses, more power to you. On the other hand I can't see why anyone would go through that much trouble to fake it. Mostly the issues with possession tend to revolve around small churches with no real standards who want the fame, and fanatical followers looking for something to blame for bad fortune or a medical condition. Most "exorcisms" I've heard about though are cases where things go wrong, and someone dies because some local minister tied some guy down and starved/beat a guy to death due to not knowing what they were doing... and really it comes down to the fact that there should be better regulation which is always a touchy subject with religion. As a general rule if there are possessions, it's even rarer than ghosts and other weird stuff, and not something that people should get bent out of shape about.
This is pretty much one of my big problem with the whole "found footage conspiracy" the idea that the government(s) are involved in supporting found footage movies, youtube horror videos, creepypasta, etc.. so that if someone actually did find and record something during this age of easy information nobody would believe it. The idea being that people dismiss the supernatural by saying "well if this existed, someone would record it on their cell phone, or have it on the internet in 15 seconds", when really we've seen an environment created where if someone did something like that it would immediately be dismissed as fake. As things stand, there isn't much need for that because the government already regulates such things to an extent (requiring "histories" of houses to be revealed), and of course it's given a fairly free reign for people to run around doing exorcisms and the like, namely by not banning it outright when a lot of exorcisms can involve things that would be criminal, if not questionable under other circumstances. What's more
anything out there is generally so low-key *IF* it exists, that there wouldn't be much reason. In real life the occasional cold spot, or a few doors moving on their own or whatever isn't exactly going to justify a massive conspiracy.
As far as this story goes, my big question would of course be at which point in this entire process did they decide to go to the media. What's more I'd want to know what kind of investigation the church did, and why they apparently think it's legitimate as opposed to one of the legions of fakes. Of course most specifically I'd want to get some of these witnesses to take a polygraph test (not being criminal, it would have to be voluntary) and probably some deep background checks, especially on the kids. The attention alone is a powerful motivator, and we're apparently looking at books, movies, etc... the first thing I would be looking at is if the kid took dance or gymnastics at some point before the incident, to be honest you don't need to be a "parkour master" to moonwalk backwards (everyone did it in the 1980s)
and kids doing jumps off walls is something kids can do fairly easily (more so than adults) especially with gymnastics training, even some school programs might involve similar things. Combining the two is cool, but it's not an unheard of trick... and of course the big witness here is Grandma who might lie for the benefit of her family and/or enjoy the entertainment, her and anyone else present might not be telling the truth about what they saw. The way how this sounds money and attention are at stake, and people will do crazy things just to get five minutes of fame, even working up a routine in hopes that's someone will eventually notice.
In short, consider me a skeptic. I could probably be convinced, but I would be a hard sell.
Also as a Christian I sort of have to bring up the obvious question. Demons as a general rule are angels who were cast out of heaven and pretty much imprisoned... they rebelled against god. Hell is designed to more or less keep them inside. The problem with the whole horror movie concept of "a gate to hell" is that it wouldn't be a very good prison if there were gateways they could just pass through at will. Even if you acknowledge the ability to occasionally escape, or be sent to earth by The Devil (arguably the second most powerful being in creation), I just can't see 200 of these things forming a conga-line in front of a portal waiting to possess people.
Now to a Satanist they might argue "god is weak" or "the devil already won" but really if that was the case chances are we'd see people getting possessed left and right every day in the middle of the street, or the world turned into a blazing inferno, or whatever else. We wouldn't be sitting here going "well, maybe it's a possession, maybe not" or discussing the merits of exorcism and how it occasionally comes up.
The bottom line here is this doesn't add up. If there are 200 demons sitting around throwing wild keggers while waiting to possess people, I think God would notice, and at least delegate some angels to take care of it (this is sort of what guys like Michael and Gabriel and the hosts of heaven are for after all). Even if one argues it's a war and both sides are in conflict, as opposed to evil being contained, 200 demons means we'd have good and evil going at it in the streets.
I can sort of see a demon getting out or being broken out occasionally and possessing a person here and there, and priests and such having to deal with it because it was fairly low key and not noticed from on high (with the point of the exorcism being to get the attention of the higher powers, so they will intervene, the power is not in the clergy, but works through them). But again... two HUNDRED demons and a gate to hell... Mean really... think about that. If an army like that got out, established a portal, and wasn't noticed, I doubt they sit around comparatively goofing off by possessing kids.
A lot of people probably won't read this far, or like that final point, but think about it. Even if your not a Christian you have to admit there are some problems here given the mythology (or what is mythology to an Atheist or follower of another religion).