I'm pretty firmly in the naturalist camp. I've had numerous psychedelic experiences. I can see how one could think such things. But I don't think we have solid reasons to start making strong claims about the supernatural.

Here's one piece of evidence out of thousands more. Consider that the psychedelic effects of LSD can be prevented simply by blocking 5-HT2A receptors in the brain [1]. This is what you would expect if a psychedelic experience is a biochemical phenomenon occurring in the brain, like that sparked by caffeine. A more powerful and much more interesting one, yes, but not something that requires talking of "god" or "universal understanding".

[1] https://blogs.scientificamerican.com/scicurious-brain/httpbl... (search the page for "block the 5-HT2A receptor")