I had a near death experience from a track motorcycle accident many years back. Long tunnel, bright light, voices, the works.

It really fucked up my atheist world view for a few years. It was incredibly vivid and real. I can still picture and hear it all perfectly to this day, had I not been had a defib before I got to the end of that tunnel I genuinely think I would have died..

I personally think that phenomenon is just a side effect of the brain shutting down due to loss of blood flow etc. It really messed me up for a while though.