I meet Justin Moon for the first time in Orlando. We are at Shot Show, one of the biggest annual gun conventions on the planet, with 15 acres of exhibitions and N.F.L.-size crowds. At the Orange County Convention Center, not far from Disney World, Justin holds court at Kahr’s booth, where the company’s notorious super-subcompact pistols, each about the size of my hand, are on display. As I look down one of the guns’ six-inch steel barrels one afternoon, Justin slides over and shakes his head. “You don’t know much about guns,” he says, “do you.”

Justin is tall, clean-shaven, and well built, with a schoolboy part in his hair and an imperious presence. He wears a fitted gray pinstriped suit with a green-and-gray-striped shirt and matching green tie, perfectly knotted and speckled with what look like white terriers. I didn’t realize it then, but I’d inadvertently aimed the gun at his chest. I put it down.

“When you picked up the gun, your finger went right to the trigger,” he says, picking up one of his own weapons. It’s apparently immaterial that the gun isn’t loaded and is missing its firing pin, just like the countless other handguns, long-range sniper rifles, and shotguns on the convention floor. “When you present a firearm, you always make sure your finger is outside the trigger guard. You never put your finger on the trigger,” he continues, holding the pistol in his palm, “until you’re ready to fire.” Pointing it at the ground, he cocks the gun and pulls the trigger, which produces a metal snapping sound. “That is the only time you put your finger on the trigger,” he says. “When you are ready.”

He’s right. I know nothing about guns; they scare me. However, my grandfather was an F.B.I. agent, so I’d seen his Colt .38 around the house and had watched him fire it at raccoons in the yard.

Justin asks what I’m doing at Shot Show. Pointing to my badge, I tell him I’m a writer from New York. “A Democrat!” he declares, nodding, as if that says everything. “I have some Democrat friends,” he tells me, “but they don’t understand any of this. It’s another world to them.”

Earlier in his life, Justin Moon was known as Kook Jin, which is what his parents, Reverend Moon and Hak Ja Han, named him. He was born in South Korea in 1970, one of 13 children and the fourth of seven sons. Like his brothers and sisters, who sometimes called him Kookie, he was brought up to be a leader in his father’s religious kingdom. The Unification Church blends Christianity with Confucianism and anticommunism and divides the world into believers and nonbelievers. The duty of the believers, according to the church, is to conquer Satan and eradicate moral decay in the world, even if it means war with the infidels. The idea is that Reverend Moon, with God’s guidance, will one day take over the earth, restoring it to peace and love.

When the Moon family moved to America from South Korea in the 1970s, critics were already calling their followers the Moonies. They were portrayed by some as a brainwashing personality cult with a thing for mass marriages and strange ideas (a highway around the world or a modern Eden in a Brazilian swamp), whose leader had a reputation for living off the work of his followers. Depending on whom you asked, there were either thousands of followers or tens of thousands; the exact number remains a mystery. Among believers, Justin’s mother and father are known as the True Parents, an acknowledgment of the reverend’s distinctive relationship with God; he claims to have spoken to Jesus.

Justin and his siblings are considered just as holy. They are called the True Children, and they have lived their lives accordingly. “The Moon kids acted like royalty,” Graham Lester, who was a member of the Unification Church from 1979 to 1995, tells me. “From their viewpoint, everyone else was a different species. Other people were not a part of God’s realm.”

Home for the True Family was a guarded 18-acre mini-castle in Irvington, New York, a tony suburb located along a sweep of the Hudson River. Named East Garden, after Eden, the estate included two smaller houses and a three-story brick mansion with 12 bedrooms, seven baths, a bowling alley, and a dining room equipped with a waterfall and pond. There were other castles and mansions too—in South Korea, Germany, Scotland, England—and few expenses were spared. The children had tutors from Japan, purebred horses, motorbikes, sports cars, and first-class vacations with blank-check spending. “The kids got whatever they wanted,” says Donna Collins, who grew up in the church. “At one point, the Moon kids were each getting $40,000 or $50,000 a month for allowance. They had wads of cash. I remember once in London where [one of Justin’s sisters] spent like $2,000 a day; I saw a drawer filled with Rolexes and diamonds.”

Justin, however, doesn’t remember that kind of indulgence. “I got nothing when I was young,” he says. “I didn’t get one dollar. I drove a beat-up Datsun.”

The True Parents were rarely around; they were off building a religion, expanding businesses, and recruiting more followers to work at those businesses. Justin grew up among church members, though the adults around him acted less like elders and more like servants, bowing as he came and went, rarely looking him in the eye.