Assuming I have interpreted your posts properly:

Gen-X claims to have had what I would call a more intense and sustained deja vu than I ever recall having.

Sam sounds like he doesn't believe in deja vu.

I wonder if it could be a doorway to evil or advancement of humankind.

Gen-X is a "believer" while Sam is a non-believer, and I am just searching for the truth with an open mind.

How does one PROVE to the other, that only one of these beliefs is the TRUTH, and which one?

Discuss...

Then see if "Deja Vu" can be replaced with "God".