This is a very intriguing aspect of the psychedelic experience to me.
Anytime I am talking to someone about them who hasn't tried them, I always say the following: "Be careful, they will convert you."
Assuming they are capable of handling them and enjoy it, everyone I've seen pursue psychedelic experiences with a positive passion inevitably has a change in belief system in some manner.
Two paths I've seen unfold, develop into a schism between the Scientists and the Spiritualists it seems. Neither side is wrong in their pursuit, but I do have a lot more problems speaking to the spiritualist, as they have the tendency to proselytize.
Usually it's a combination of both, with one "belief" set reigning supreme in the person's belief system. I fall squarely on the Scientist side of the fence, but mushrooms, DMT and ketamine definitely bring out my spiritual side. On those substances is the only time I feel whatever spiritual feelings of connectedness that I assume true believers of the worlds religions feel when they go to church/temple and in general practice their beliefs.
I have friends who are spiritualists, who speak of vibrational energy levels and chakras. Or speak of the spirits of their ancestors manifesting themselves into the body of a currently living person.
One guy I knew after beginning his own psychedelic journey was converted to the thought that through scientific research into them we could obtain transcendence.
I listen respectfully, question when appropriate, but otherwise try not to upset someone's beliefs about psychedelics anymore than I would try to upset their beliefs about Christianity/Hinduism/etc.
Then you have the degree at which they believe psychedelics should be used to help mankind. Timothy Leary I'd classify as a Scientist (from what I've seen) who believed everyone should use them liberally to bring world peace and understanding. McKenna was a spiritualist who preached liberal usage to return to our partnership societal origins. Then there are others who believe that psychedelics should be treated with respect and discipline, as if a "holy sacrament".
I definitely agree with those who believe psychedelics should be treated with the respect/discipline as if they were a holy sacrament. They are not "holy" to me, but simply an incredibly powerful tool that requires training to use properly for the same reason we require drivers licenses to drive, or conceal carry permits to walk around town with a gun.
The book by Fadiman, "The Psychedelic Explorer's Guide" is a good book to read to learn how trip safely/positive and train sitters how to handle the experience. Carlos Castaneda's Don Juan series, despite the very "spiritualist" theme, is very good at showing how and why training in the use of psychedelics is wise.
Even if all psychedelics were to lose their scheduled status, I would fully support any effort to add -reasonable- restrictions on their availability. I think one should be taught about them, and guided in their use with a trained sitter, before being legally allowed to pursue them on their own without supervision.
And knowing the psychedelic user base and their general culture... it's very likely many of the authorized guides would do the service for free. I know I would.
Psychedelics are amazing... but to me they are simply a tool. A very powerful one that must be used with care and respect.