I recall reading, some years ago, that the US Air Force was able to induce 'near death experiences' in pilots who had lost consciousness when using the machine that simulates high speed flight and puts them through increasing G-force. There was a book relating the experiences, if I am not mistaken.
I don't know about life after death, I try not to commit to a belief that I cannot justify but I have no particular desire to deny or disprove anyone else's experiences or beliefs, especially when it comes to the metaphysical. We're only beginning to understand the human brain, but we already know that it can conjure up imaginary experiences that feel real and that it can do some very strange things when it is chemically altered or otherwise damaged. It's not an entirely reliable tool all by itself.
I'm pretty sure that, if there is a god or gods, it isn't anything like the ones we've dreamed up over the course of human existence. At least, I certainly hope not. They sound a lot like a typical human if you gave him unlimited power. And seeing how atrocious we act when we have even limited power, it would be very ugly. Very bad.