I would conclude I was hallucinating. I've hallucinated before, it seems very real. Completely real, in fact. So if I saw a guy claiming to be god, no matter what he told me, I'd conclude that *I* was crazy. Worse, anything he might do to prove he's a god -- miracles and what not -- would just make me all the more sure I was nuts. I'd probably call 911. (In the U.S., that's the emergency assistance number)
That assumes s/he would leave you the time for a second thought about the experience, out of the experience. While you are hallucinating or dreaming you don't know or suspect you are (unless it's part of the hallucination/dream or you are already waking up).
Or that the experience would not change even your waking mind; or that you'll not have fallen in love with your experience (however gruesome it might objectively be) and half-consciously choose to believe it rather than reality. A "rational mind" is a frail barque on a deep ocean.
It's the kind of thing I often think of when I hear or read from people saying "what they would say to God, ask God if..." not wondering what would remain of "them" if... When Job asked to argue with God he was a bit more cautious, by setting in advance the conditions for a meaningful dialogue (13:20ff):
Only grant two things to me,
then I will not hide myself from your face:
withdraw your hand far from me,
and do not let dread of you terrify me. Then call, and I will answer;
or let me speak, and you reply to me.
Actually, as far as our present "mind" is concerned, the only alternative to the uncertainty of becoming is the symmetrical uncertainty of writing. Cf. 19:23:
O that my words were written down!
O that they were inscribed in a book!
O that with an iron pen and with lead
they were engraved on a rock forever!
But then the only meaningful encounter (between who/what I am, now, in "God's absence," and "God") is deferred. Mediated by an ambiguous text to be read in absentia.
