I really don’t think the word spiritual precludes atheists, you could even read it as “the human spirit”. The point is just that you need some framework to ground yourself. Plenty of people have “spiritual” beliefs based purely around the many-worlds interpretation of quantum mechanics or even simulation theory.
I'm an absolute atheist and philosophical nihilist and I have done psychedelics and I've never had a problem with them. Typically find the experiences positive. So we have at least one counter-example.
Belief in spirits is just as absurd as belief in deities, which are just a specialized category of spirit as far as these things are usually classified anyway.
spirituality doesn’t have to mean you believe in spirits in the sense of ghosts etc. I believe that if that’s where the definition of exploring one’s own inner world ends, then that person has missed the point.
If you don't mean to suggest you believe in some strange metaphysics without any grounding in reality, why do you call it spirituality? What "inner world" are you "exploring"? Can that be done in plain language without any mysticism? Why or why not?
we are monkeys following logic that was determined by other monkeys. our experience of reality is equivalent to that of a brain in a jar. blind belief is blind belief whether placed in science or religion. breaching the gap of blindness necessarily involves a leap to test ideas with personal faith. such a notion is not necessarily compatible with an atheistic perspective insisting reality is solely that which may be verbally quantified by monkeys. a dog knows to sit on command but has no idea about the concept of sitting, does that make the concept of sitting unreal?
It doesn't have to be. Searching out the unknown is seeking out new knowledge, seeking to diminish ignorance. You don't need to believe in higher powers or anything like that to search for new knowledge. Spirituality is a shortcut to a unverifiable, unfalsifiable knowledge that some explanation for phenomena exists, but not at all the kind of thing anyone actually interested in truth or expanding their own knowledge would use to explain anything.