The Science of Sacred Experience
The ancient claim was that a sacred substance could open a direct door to the Divine. For sixty years, scientists have put that claim to the test — in chapels and in clinical labs, with divinity students and with ordained clergy. The findings are remarkably consistent: under the right conditions, psilocybin reliably occasions experiences that participants rate among the most spiritually significant of their entire lives.
The Good Friday Experiment
Divinity Students Meet the Mystical
On Good Friday 1962, psychiatrist and ordained minister Walter Pahnke — working under Timothy Leary at Harvard — gave twenty Protestant divinity students a capsule before a chapel service at Boston University's Marsh Chapel. Half received 30 mg of psilocybin, half a placebo, in a double-blind design.
Those who received psilocybin reported, far more than the controls, the classic hallmarks of mystical experience: unity, sacredness, transcendence of time and space, and a deep sense of encountering the holy.
In a 25-year follow-up published by Rick Doblin in 1991, all but one of the psilocybin subjects described the day as a genuine mystical experience and one of the high points of their spiritual lives — though Doblin also documented methodological flaws, including one subject who needed to be sedated.
The Johns Hopkins Rediscovery
Mystical Experience, Under Controlled Conditions
Four decades later, Roland Griffiths and colleagues at Johns Hopkins revived rigorous research with a landmark double-blind study of 36 psychedelic-naïve volunteers, published in Psychopharmacology. Many were active in religious or spiritual communities.
Two-thirds of participants rated the psilocybin session among the five most personally and spiritually significant experiences of their lives — comparable to the birth of a first child or the death of a parent.
At a 14-month follow-up (Griffiths et al., 2008), 58% still rated the experience among their five most spiritually significant, and reported lasting positive changes in attitudes, mood, and behavior that friends and family independently confirmed.
Encounters with God
Four Thousand Accounts of the Divine
Griffiths' team surveyed more than 4,200 people who reported a personal encounter with “God” or “Ultimate Reality” — comparing those that arose naturally (through prayer, meditation, or spontaneously) with those occasioned by psilocybin, LSD, ayahuasca, or DMT.
Those who encountered the Divine without drugs most often named it “God”; the psychedelic groups leaned toward “Ultimate Reality.” But across both kinds of experience, the encounters were rated among the most personally meaningful and spiritually significant events of people's lives.
Strikingly, the majority of participants who had identified as atheist before the experience no longer did so afterward — and most attributed enduring increases in life satisfaction, purpose, and meaning to the encounter.
The Clergy Study
When Priests, Pastors and Rabbis Took the Sacrament
The most directly relevant study took a decade to reach print. Johns Hopkins and NYU researchers recruited ordained leaders from major world religions — including Christian priests and pastors, rabbis, and others — and guided each through two supervised psilocybin sessions (20, then 20–30 mg/70 kg) about a month apart.
Compared with a delayed-treatment control group, those who received psilocybin reported significantly greater positive changes in their religious practices, attitudes toward their own faith, and effectiveness as spiritual leaders.
79% gave strong or extreme endorsement that the experience increased their effectiveness in their religious vocation, and most reported a deepened “sense of the sacred.” Published at last in Psychedelic Medicine in 2025, after the death of lead author Roland Griffiths.
What the Evidence Suggests
Across six decades, from divinity students to ordained clergy, one finding holds steady: the sacrament does not merely produce visions — it produces durable, life-altering encounters with the sacred. For a tradition that once promised a direct, experiential path to the Divine, modern science is quietly confirming what the ancient mysteries always claimed.