Moses saw a burning bush. Paul saw Jesus on the road to Damascus. St. Teresa had ecstatic visions. When psychologist William Richards looks at religion, he sees mystical experiences everywhere.

The same sort of experiences, he reasons, that come from mind-altering drugs. That's why he's giving magic mushrooms to religious leaders, for a research project based at Johns Hopkins University and New York University.

"There are - it's so hard to put this into language - sacred eternal experiences that the human being is capable of having. They seem to be at the origin of most religions," he said.

"What we call the eternal seems incredibly real."

In the Hopkins and NYU study, two dozen clergy - including priests, pastors and rabbis - are taking controlled doses of psilocybin, the drug found in psychedelic mushrooms, under the watchful eye of scientists.

Richards won't say much about what has been happening when the clergy try the drugs, in Baltimore and New York settings that resemble living rooms more than laboratories.

That's all part of the ongoing study, which he and his fellow researchers will eventually publish.

What he will say is that when he's administered psilocybin to research subjects before - studying its potential as a treatment for anxiety and depression - religious imagery tends to come up a lot.

Through this study, he hopes to learn about the drug's effect on spiritual practice; he'll follow up with the clergy for two years to see how their approach to the mystical is or is not altered by their encounter with the drug.

"People see incredible things with their eyes closed that are often very, very beautiful," including visions of Jesus, he said.

"That seems to happen whether people are of religious training or not. It doesn't seem to be something that's learned. It seems to be something that's genetic."

Religious authorities have typically not looked favorably upon drug use. Some faiths, like Islam and Mormonism, ban all intoxicating substances.

The United Methodist Church, the nation's largest mainline Protestant denomination, includes in its Book of Resolutions, "Psychedelics or hallucinogens, which include LSD, psilocybin, mescaline, PCP, and DMT, produce changes in perception and altered states of consciousness."

"Not only is medical use of psychedelics or hallucinogens limited, if present at all, but the use of these drugs may result in permanent psychiatric problems… Therefore, as The United Methodist Church: We oppose the use of all drugs, except in cases of appropriate medical supervision."

When the revered rabbinic leader Menachem Schneerson was asked in a letter about LSD in the 1960s, he wrote back that the drug "is not the proper way to attain mystical inspiration, even if it had such a property."

"The Jewish way is to go from strength to strength, not by means of drugs and other artificial stimulants, which have a place only if they are necessary for the physical health."

But the Hopkins researchers have found Christian, Jewish and Buddhist clergy willing to participate anonymously in their study. Richards says he's still hoping to recruit Hindu and Muslim leaders as well.

To reduce the risk of adverse drug effects, the researchers first screen clergy for a history of heart, kidney and psychological illnesses.

Richards first tried psilocybin when he was a research subject himself, a 23-year-old graduate student in Germany in 1963.

Since then, he has conducted numerous studies on the drug's effects, becoming convinced that even one-time use helps patients reduce the severity of anxiety and depression.

He said he participates in conversations with officials at the Food and Drug Administration about what information the agency would need to see if it were to ever consider moving psychedelic drugs, including LSD and peyote, off the Schedule 1 list of controlled substances that have no accepted medical purpose.

He compares drug trips to other "unique states of human consciousness", including sensory deprivation, overstimulation and even childbirth.

When people experience religious visions, he says, those visions are always influenced by bodily chemistry - whether brought on by stress, by fasting, or in the case of religious groups that employ drugs like peyote in their rituals, by substance use.

That's not to say that God isn't working through the chemical compounds.

"The deep mystical experiences are always discovered as gifts received," he said "That's what we call grace, religiously."

What the pastors and rabbis report after their drug experience isn't just what Williams jokingly refers to as "the tie-dyed T-shirt effect". They draw religious inferences from their trips.

"One of the spiritual insights that occurs reliably is the sense of interconnectedness of us all, the family of man… which really, I think, is desperately needed in this world. We're getting so isolated and afraid of diversity," he said.

Most research subjects who report positively on their drug experiences don't express much interest in using the drug again anytime soon, he said.

But they do report applying the insight they gained from the drug, like the connection of diverse men and women, to their everyday lives.

"These spiritual experiences, they're more than just feel-good experiences. They really give you knowledge and they change people."

He said he believes these clergy members will strive to attain the same sort of visionary moments they experience on drugs in the laboratory through other spiritual practices, like meditation.

Their drug trips will motivate them, he predicts: "They know there is a top up on the mountain, and now they're willing to hike up there."

Does he think religious people can have the same sort of visions without pharmacological help? "Yes, but it's much harder".

2017 © The Washington Post

This article was originally published by The Washington Post.