GARRET WAS BORN IN 1975 as Achim Schmid in Mosbach, Germany, to a marriage that was already breaking apart. When he was 8, his father died of lung cancer. His mother, who never remarried, would grab a bottle of alcohol after work and lock herself in her room all night. Given his family’s reputation, other children’s parents didn’t allow them to play with Garret. Kids bullied him in school. Then one day, he heard schoolmates laughing over anti-Semitic jokes, and he began dropping those jokes too, hoping to score laughs.

In post-war Germany, the mere mention of Hitler or national pride drew giggles and gasps. Garret liked that attention. By age 13, people were calling him “the Nazi kid,” but anything was better than being the bullied kid: “Suddenly, I had an identity. I was not a nobody anymore.”

As a young teenager, Garret fell in love with far-right skinhead bands that sang about nationalism and feeling misunderstood and that raged against authority, Jews, blacks, and immigrants. At 19, he began performing in a skinhead band that traveled across Europe.

In 1998, Garret joined a Klan group in Germany and later opened his own chapter. The age of the internet was also booming. Garret met American Klansmen online who identified as Christians, and he peppered them with questions: How can you be anti-Semitic yet pray to Jesus, a Jew? They said Jesus was not Jewish, but white. They claimed that black people are “beasts of the field,” that Jesus was blond, that enslaving or exterminating nonwhites would hasten Christ’s second coming.

That sounded ridiculous to Garret, so he pored through the Bible and found the opposite: The Bible teaches that all human beings are created in the image of God. It talks about welcoming foreigners and treating them with empathy and justice. Jesus was kind and compassionate to the Samaritan woman, who was part of an ethnic group the Jews abhorred.

Garret began wondering: What if nothing made sense because his beliefs were wrong? What most people don’t realize is that “everyone in hate groups have doubts,” Garret said. But whenever he expressed doubts, other Klansmen shushed him: The Jew-controlled media’s tricking you. Satan’s deceiving you. “It’s like standing on quicksand,” Garret recalled. “The more you try to get out, the deeper you sink in.”

By then, police were raiding his house, digging for evidence of domestic terrorism and hate crimes. That spooked him. In 2002, he resigned as grand dragon of his Klan group and moved with his family 100 miles away to another town, where he rented the only affordable house available. Problem was, his landlord was a Muslim immigrant from Turkey. That man turned out to be Garret’s “someone.”

One night, the landlord invited him to dinner with his wife and two children. As a penny-strapped stranger in a new town, Garret felt forced to accept. His inner conflict exacerbated into a full-out internal warfare when the landlord’s wife placed a steaming bowl of Turkish fish soup before him. He had heard that rejecting these people’s food is a grave insult. But if he ate this soup—he was quite convinced that he might vomit before his hosts.

Finally, Garret blurted out, “I’m sorry. I don’t like fish soup.” And then he held his breath, but the landlord’s wife simply smiled and took the soup away. For the rest of the night, they were just as nice and gracious. Garret walked away that night in tears: “Everything I had expected did not happen. I felt so small and wrong.”

Garret had always thought his ideology was based on love: love for his race, his family, country, heritage, and culture. But the more he met people of other races and ethnicities, the more he realized how much he had lived in ignorant hate: “We went to bed with hate, we woke up with hate.”

That hate is all-consuming: It seeps into every part of that person’s life and identity. That’s why it’s so hard for some to separate themselves from their ideology—without it, who are they?

DECADES AFTER DENOUNCING white supremacism, Tim Zaal still battles guilt, shame, and self-hatred. Born and raised in a majority-white suburban neighborhood in Los Angeles, Zaal was mostly home alone while both his parents worked. The loud, crazed, violent punk music scene of the 1980s pumped him out of his boredom and loneliness. He had always felt out of place in school—but the punk rockers? That was his tribe.

Once all his punk rocker friends left town for college or military service, Zaal went searching for another tribe. He drove 200 miles down to San Diego to visit Tom Metzger, leader of White Aryan Resistance (WAR), a neo-Nazi group. He began reading literature such as The White Man’s Bible, The Turner Diaries, and monthly WAR newsletters: “I became a true believer. I believed that the white race was in decline, and in order to save the white race, I had to do whatever it took.”

So he beat up gay men. He harassed minorities. He plastered Nazi flyers in Jewish neighborhoods. Once, he terrified a little black Girl Scout by chasing her down the beach. Then on Memorial Day of 1989, he and some other buddies attacked an Iranian couple pushing a baby stroller at a supermarket parking lot. They had mistakenly identified them as Jews.

The incident splashed headlines across Southern California and sent Zaal to jail for a year. During trial, seeing the hate on his opponents’ faces further radicalized him: “It was scary. I thought all these powerful Jews were out there to get me. So I kicked [the hate] up a few gears.”

But over time, that constant hate became exhausting. When his then-wife told him she’d kill their own son if he had a single drop of nonwhite blood in him, Zaal realized how fanatical they had become. Then one day, when his son loudly called a black man a racial slur in a supermarket, Zaal felt his zealotry wither under the nasty stares. At the time, he was also working on construction sites alongside nonwhites who treated him with friendliness and respect. How could these nice people be his enemies? “It just didn’t make sense to me anymore.”

Today Zaal is a soft-spoken, mellow 6-foot-3 giant who works with students with disabilities. It’s almost impossible to envision Zaal as a drunk neo-Nazi who once kicked people with razor-blade-studded boots. He’s been married to a Jewish woman for 20 years and is relieved that his son didn’t follow in his extremist footsteps.

But he worries for the next generation. When masses of white young men marched with tiki torches in Charlottesville, Va., chanting, “Jews will not replace us,” Zaal recalled his younger self, but these folks looked different. They were clean-cut “ordinary Americans” in pressed khakis and polo shirts; they didn’t wear white robes or carry Nazi flags or shave their heads; they didn’t burn crosses and U.S. flags; yet they were repeating the same hate and conspiracy theories Zaal once did.

That’s why Tarrants says it isn’t enough to advocate against hate and racism. He grew up under similar social and political currents in the 1950s and ’60s. At the time, communism was a serious threat, and the country he knew was changing faster than he could understand it. When public schools no longer allowed prayer and Bible reading, and forced students to desegregate, Tarrants was scared, angry, and confused. So when propaganda newsletters on campus presented simplistic answers to his questions, he got sucked in—all the way to terrorism and prison.

The biggest difference between Tarrants’ time and today, however, is that people are much better connected. Decades ago, extremist groups recruited members through flyers and mail-order VHS tapes, which limited their reach. But with the emergence of social media and gaming platforms, anyone with a device can tap into an unlimited pool of radical ideas. These online echo chambers affirm people’s twisted worldviews, and those who once suppressed budding prejudices can now voice them online, grooming each other into violence.

Not even church members are immune to such influences. The 19-year-old shooter who attacked a synagogue in San Diego was a member of a conservative evangelical church.

“There’s no way to avoid it,” Tarrants said, arguing that how the Church responds can change the tide. “The Church needs to stand and be seen as a body in society where people love one another across all these barriers that divide us—race, economics, culture, politics. If we do that, that’s a powerful witness of light to the darkness in this world.”