Humans are animals of basic chemical nature. Our bodies are composed of chemicals which transform our thoughts and affect the Spirit, as much as the Spirit affects the Body.
Some early records of psychedelic usage are from the Ancient Greeks who had many ceremonies revolving around hallucinogens, one of the major being the Eleusinian Mysteries which involved a brew of a fungus ‘ergot’ that contains the chemical LSA (which LSD is derived from); Aristotle, Plato, Cicero, etc… all went through this ceremony. There would be no modern philosophy if it weren’t for Acid.
The Aryans who brought Hinduism to the Indian sub-continent had many psychedelic traditions, their most sacred brew being Soma; researchers are not yet certain exactly which psychedelics were in Soma but almost certainly it contained Amanita Muscaria, a very psychedelic mushroom; sadly, even the Vedic Hymns announce that the exact plant(s) was/were lost to the Ancients themselves over time, so guesses as far as Ephedra can be found. In any case it was quite psychedelic and we owe Hinduism to the teachings of Mother Nature.
Buddhists revere the Blue Lotus flower. The meditation position is called the lotus position, Buddha comes from a Lotus pedal. Blue Lotus is a psychedelic plant – obviously revered due to this.
Natives of the Amazon brew Ayahuasca which contains a high amount of DMT – a chemical referred to as the Spirit Molecule and thought to be responsible for much of the centralization of brain functioning. The effects on the mind are otherworldly and spiritual, hence the nickname.
There is a theory floating around that the pre-Humans who discovered fire did so while high after ingesting Psilocybin Mushrooms. To anyone who has ever experienced the child-like awe and wonder at the world around them while under the effects of Psilocybin know this may very well be the case.
Psychedelics are at the core of the Human Spirit; we are bonded to Mother Nature in a beautiful way and in order to revere the true majesty of life and consciousness we must accept her gifts and use psychedelics to achieve trance states of Oneness with the Universe. To not do so is a sin for the essence of consciousness is curiosity, discovery, and love; what makes one love more than discovering the truth of that which made them curious?