I mean, NDEs are what happens when a brain is starved of oxygen for a while. If you just stand up suddenly, sometimes the blood will dump out of your brain for a few seconds, and you can have tunnel vision, feel disoriented, see weird flashes of light, feel dislocated.
So, just imagine that effect but x10. It would pretty easily explain the NDEs I've read about. And Christians are trained from childhood to attribute any strange physical or emotional feelings to the presence of a god, so it makes sense their brains would make that association while experiencing extremely strange and disorienting sensations.
I've never quite understood why this is such a mystery for people. Or why it's any kind of evidence for the supernatural. Then again, I've never almost died due to oxygen deprivation. I imagine it leaves quite an emotional impression.