So we base our reality as a society off of what can be observed consensually by enough people. We tend to not believe in what can only be experienced by one person. There is lots of scientific research coming out with mushrooms and lsd where if participants are given a high enough dose a spiritual or mystical experience is very likely. If enough people can experience this as a function of ingesting a particular substance, than it can be considered a state of consciousness or function of the brain instead of one person’s delusions, right? It does not matter if it is “just chemicals” so are emotions, love, the idea of having a self, but we consider those to be real because many people verify the experience of them.