Don't believe anything you can't demonstrate
A long time ago in a Zen book I read a phrase that I really like, and it goes something like this:
"Don't believe anything you can't demonstrate for yourself."
What that means is that you shouldn't believe anything anyone writes, including myself, unless you can demonstrate for yourself that it's true. I personally promise that everything on this website is true, but in reality, you have no way of knowing that for sure, so rather than believe what I write verbatim, the message (and lesson) is to only believe it 100% if you can demonstrate it for yourself.
I may say that I have out of body experiences (OBEs), that "I" have gained consciousness while laying in bed next to my physical body, that "I" have heard my physical body snore while my consciousness was floating around in the same room, and that "I" have succeeded at the card test at least six times, and I state those events as fact and promise they are true, but you should not 100% believe me until you can demonstrate this ability to yourself.
(I could get into a discussion of "faith" here, and perhaps a Zen student should have faith in their Zen master, but that's another story for another day.)
Until then I hope you find my stories and quotes from books interesting, and I hope they offer hope for what human beings can achieve. I also hope these stories convey what seems so obvious to me: Whatever we are, we are much more than just our physical bodies.