Furthermore, even if you are correct in that there isn't a more logical explanation for possession (there is, obviously, but let's pretend for a moment that it's not for the sake of argument), that doesn't prove an entire religion. Much like anything else, Christianity needs positive proof of its specific claims, not evidence that a competing hypothesis is false. Proving an alternative false without proving your thing means we don't know the answer, not we know that your thing is correct. With this in mind, to prove Christianity is true, you need to objectively prove that a deity as described in the bible exists, is the only one of its kind, created the entire universe, chooses whether or not to have people tortured for all eternity according to the criteria laid out in the Bible, and last but not least, had a human avatar of itself nailed to a couple of planks by a regional superpower just over 2000 years ago.
Again, disproving contradictory ideas is nowhere near good enough for us to accept Christianity. You need to present objective evidence that Christianity is true (not just something vaguely supernatural, but specifically Christianity).
Of course, you're not going to do that. Not least because you can't, because no such evidence exists in the first place. Even Christians and other religoes are largely aware of this. That's why they never go that route in the first place, and instead just appeal to emotions. Hence why they try to lay claim to morality, or convince people that blind faith for the sake of blind faith in unsubstantiated bullshit is a somehow a good thing that means you're totally a good person. But no, if you think you can succeed where religious nutjobs of all flavours have tried and failed for all of recorded human history, I for one would love to hear it.