It's interesting you should mention the chemical dmt

It's known in the UK as "the God trip". You take it and have the most intense hallucinations so you can actually feel that you are in heaven, hell, and reality completely leaves you. It doesn't last long so people can do it in a lunch break.

But, if these intense spiritual experiences can be brought about at any time by ingesting a chemical, it shows the experience is totally not spiritual, but just our brains going crazy to a compound.

It also calls into question what we call reality if our perception of it is so easily warped .