I have religious visions and I know the difference between hallucinations and religious visions. I am a full veteran of the psychedelic '60's and have had enough experience with psychoactive chemically induced hallucinations to be certain that my own religious visions are of a different order, one big difference being they come unbidden without drug inducement and they aren't random images continually changing form as drug induced hallucinations do.
God gave me the image for Paxcalibur, Sword of Peace, and after wowing and being honored by over 500 Christian Nazareans at Easter in 2003, now Paxcalibur resides in Nazareth, Israel, as the world's most spiritually powerful religious icon having the ability to "speak" God's message of peace without necessity of language to anyone who sees it. My vision of Christ Josephine, a Native American Spirit Woman I saw five years before I knew anything about the Lakota's prophesy of the return of their Savior and founder spirit woman White Buffalo Calf Woman. Now I am a grandfather to three children who are direct descendants of the Lakota's most famous spiritual warrior leader, Sitting Bull and am working with the Lakota tribes on an economic development and ancestral land recovery enterprise. Could all this have happened because of drug caused illusions in my mind? Sometimes God speaks and gives human beings visions to guide them to new ways of being.
From what little I understand of hallucinations, they aren't always drug-induced.
The human mind is very powerful; you'd be surprised at how much it can trick you.