Religious use of drugs and alcohol
Hindu gurus
Cannabis has been used by Hindu gurus as early as 1500 BCE. The use of the herb is in worship of the god Shiva, also known as the supreme god. Not a bad way to worship your god as you're digging your way through a bag of crunchy Cheetos. The smoking of cannabis is said to cleanse sins, unite one with Shiva, and avoids the miseries of hell and the after-life.
Mazatec shamans
Salvia divinorum, also known as the Sage of the Seers, is a herb used around Oaxaca, Mexico by shamans. These shamans take the herb in tea form, crushing the plant and infusing it with hot water, or simply chewing the leaves. It's used for religious healing ceremonies and provides the user with a psychedelic experience that can include uncontrollable laughter, becoming an object, and strange feelings of motion.
The summary, describing the sacred history of Ayahuasca, the Fly Agaric mushroom, Peyote, Damiana, Morning Glory and Hawaiian Baby Woodrose seeds, Kratom, Khat, opium, wine, and the mysterious Kykeon, continues here.