Why do Christians trust YHWH?

[Esquilax]

So everything subjective is necessarily irrational?

No, that's why I added everything after the word "barring." It'd be irrational of me to accept the existence of a thing based on somebody else's subjective experience, but if I had one myself then I might be okay. "Subjective" is the same as "first person," after all.

That said, I'm clearly not getting this experience just on my own, so that means either you're seeing something that isn't there, or I'm not seeing something that is. If it's the latter, then there's at least the possibility that I could be prompted into seeing that thing.