Fertility cults worshiped rain for its rebirth of nature and agricultural life. The Essenes were fascinated with the sacred mushroom (Amanita Muscaria) which appeared hours after rain. Microscopic spores were unknown at the time. Rain was viewed as semen of the gods and the mushroom symboled a heavenly a penis (son of god) because of it's swift erection after rainfall. Ingesting the mushroom (communion) caused hallucinogenic effects and those of the sex-fertility cults believed they were enlightened with God's knowledge, thus it was a sacred plant.

This is the work of John Allegros, the only agnostic on a team to decypher the Dead Sea Scrolls. His work is banned from publishing, however, you can download his book "The Sacred Mushroom and the Cross" on the web in PDF. Reading his work is akin to discovering the holy grail - it was for me.