He wasn't always this way. Suelo graduated from the University of Colorado with a degree in anthropology, he thought about becoming a doctor, he held jobs, he had cash and a bank account. In 1987, after several years as an assistant lab technician in Colorado hospitals, he joined the Peace Corps and was posted to an Ecuadoran village high in the Andes. He was charged with monitoring the health of tribespeople in the area, teaching first aid and nutrition, and handing out medicine where needed; his proudest achievement was delivering three babies. The tribe had been getting richer for a decade, and during the two years he was there he watched as the villagers began to adopt the economics of modernity. They sold the food from their fields—quinoa, potatoes, corn, lentils—for cash, which they used to purchase things they didn't need, as Suelo describes it. They bought soda and white flour and refined sugar and noodles and big bags of MSG to flavor the starchy meals. They bought TVs. The more they spent, says Suelo, the more their health declined. He could measure the deterioration on his charts. "It looked," he says, "like money was impoverishing them."

The experience was transformative, but Suelo needed another decade to fashion his response. He moved to Moab and worked at a women's shelter for five years. He wanted to help people, but getting paid for it seemed dishonest—how real was help that demanded recompense? The answer lay, in part, in the Christianity of his childhood. In Suelo's nascent philosophy, following Jesus meant adopting the hard life prescribed in the Sermon on the Mount. "Giving up possessions, living beyond credit and debt," Suelo explains on his blog, "freely giving and freely taking, forgiving all debts, owing nobody a thing, living and walking without guilt . . . grudge [or] judgment." If grace was the goal, Suelo told himself, then it had to be grace in the classical sense, from the Latin gratia, meaning favor—and also, free.

By 1999, he was living in a Buddhist monastery in Thailand—he had saved just enough money for the flight. From there, he made his way to India, where he found himself in good company among the sadhus, the revered ascetics who go penniless for their gods. Numbering as many as 5 million, the sadhus can be found wandering roads and forests across the subcontinent, seeking enlightenment in self-abnegation. "I wanted to be a sadhu," Suelo says. "But what good would it do for me to be a sadhu in India? A true test of faith would be to return to one of the most materialistic, money-worshipping nations on earth and be a sadhu there. To be a vagabond in America, a bum, and make an art of it—the idea enchanted me."

There isn't enough space in Suelo's cave for two, so I sleep in the open, at the edge of a hundred-foot cliff. No worries about animals, he says. Though mountain lions drink from the stream, and bobcats hunt rabbits under the cottonwoods, the worst he's experienced was a skunk that sprayed him in the face. Mice scurry over his body in the cave, and kissing bugs sometimes suck the blood from under his fingernails while he sleeps. He shrugs off these indignities. "After all, it's their cave too," he says. I hunker down near a nest of scorpions, which crawl up the canyon walls, ignoring me.