AB,
The existence of the devil is as real to me as the existence of New Zealand is to you.
Sadly, I believe you. While for thinking people asserting "the devil" is as mad as a box of frogs, the important part of that sentence is, "for me". For
you I'm don't doubt the devil is a real as Jack Frost is real for Fred or the Man in the Moon is real for Charlie. We can each have personal, subjective beliefs about anything if we want to.
The difference though between these types of belief and "believing" in the fact of New Zealand is that, for the latter, our subjective opinions have no relevance - we can each visit the place if we want to, which makes New Zealand an objective truth.
Your problem in other words is not so much that you believe in palpable nonsense as personal truths, but rather that you pitch up here (and presumably elsewhere too) and assert them to be objective truths for the rest of us too. And as your arguments for them collapse in heaps of logical fallacy when you try them, assertion is I'm afraid all that's left to you.
Keep it you yourself, and it's no-one's business but your own; overreach by insisting that this devil is true for me too though and you'll keep crashing and burning. Sorry, but there it is.