Half a century ago, Thomas Tarrants — a child of Mobile, Ala. — felt like the country was changing for the worse. The civil rights movement infuriated him. His hatred of African Americans and Jews led him straight into the arms of the Ku Klux Klan. Hate led him to participate in a group that bombed Mississippi synagogues. Hate led him to prison.

Now, he recognizes the same anger in a growing number of young men in 2019. And Tarrants, who renounced his white-supremacist past decades ago, feels compelled to warn others away from the path he traveled.

The solution he proposes: Christianity.

“I’ve shared over the years, from time to time, how God changed my life. I’ve seen the tremendous encouragement it brings to people. It helps them see that God is real and active in the world,” he said. “And if you’re a believer, you’re going to have friends across racial groups.”

Tarrants’s grim conviction — that the Trump era bears many of the hallmarks of the time that prompted him to join the KKK — has led him to tell his story and urge his religion as an antidote, in a book he published last month.

“People can be seduced by these things when the climate is right,” he said, comparing the current era not just to the 1960s but to Nazi Germany. “There is no reason that cannot happen again. It’s a very shocking thought. . . . I don’t want to prophesy. I think we’re seeing things today that should be causing people to ask questions.”

Tarrants’s own story is a turbulent one. His relationship with his father was troubled, and he found role models instead as a teen in his white-supremacist neighbors. Carrying a bomb to a Jewish civil rights leader’s house in 1968, he was stopped by FBI agents investigating his KKK group, which had been terrorizing Mississippi’s Jews. The FBI chased Tarrants and his companion, then engaged them in a bloody shootout: The woman with Tarrants was killed, and he was shot four times at close range. He survived.

In prison, at first he read “Mein Kampf” and other books that fueled and furthered his worldview. Then he started reading Plato and Aristotle. And then scripture.

He became convinced that he had gone drastically astray.

Thomas Tarrants (J Edward Glancy/J Edward Glancy)

With the support of a Jewish community leader who believed in his redemption, Tarrants secured early release from prison after eight years behind bars. He moved to the District in 1978, where he went to work in Christian ministry. He eventually obtained a seminary degree and a doctorate, pastored a nondenominational church in D.C. for five years, and spent the past 21 years working at the evangelical C.S. Lewis Institute in Washington, including 12 years as its president.

Today, he is a soft-spoken, mannerly 72-year-old who picks his words deliberately as he converses about theology and about the research statistics he’s always reading, tracking the rise and fall of hate crimes and bias in America. Only a hint remains of his Southern accent.

Chris Morris, the current chair of the board of the C.S. Lewis Institute, remembers when he first learned of Tarrants’s criminal record when Tarrants talked about it on a Christian retreat led by the organization in 2005.

“My first reaction was, ‘Really?!’ I wasn’t sure what to make of it. . . . Why would you ever want to be in a room with somebody who did what he did?” said Morris, who is African American. He recalls asking Tarrants tough questions at that retreat and watching his behavior in the years that followed. “We chatted about it very openly. The question was, was he sincere in his beliefs? And there’s no question in the changes.”

Now, the men are good friends, who spend lunches talking about the problem of racism. They even spoke together at a corporate Black History Month event.

Tarrants’s new book, “Consumed by Hate, Redeemed by Love,” has mostly attracted praise from evangelical Christian leaders, though John Grisham — who based his novel “The Chamber” on the bombings that Tarrants participated in — said on the book jacket that his story is “riveting, inspiring” and a “measure of hope.”

Tarrants will be donating the royalties from his new book to the National Christian Foundation, which supports numerous ministries, not an anti-discrimination group. He occasionally gives talks about tolerance and wrote a previous book about his story. He does not work with groups like the Anti-Defamation League or the Southern Poverty Law Center (both of which declined to comment on Tarrants), although he follows their work closely.

Groups including Life After Hate successfully work on deprogramming members of hate groups, but Tarrants does not aim his message at current-day members of such groups. Any attempt he might make to dissuade white supremacists would be futile, he says: “Knowing the mind-set of folks like that, they’re not interested in hearing anything from someone like me. I’m seen as a traitor to the cause.”

Instead, he said, his intended audience is Christians, and he hopes to inspire them by sharing his own transformation. If Christians were practicing their faith more deeply and truly, he believes, they would be forging meaningful, loving relationships across racial differences. They would be alert to the signs of a lonely young man growing radicalized in time to steer him differently. They would vote for politicians who won’t embolden racists and prevent hate crimes by supporting policies like a ban on private ownership of assault weapons, which Tarrants advocates for.

People who don’t follow Jesus’ instructions to love your enemies, and to love your neighbor as yourself, he argues, aren’t really Christian, even if they think they are. “There’s a lot of it in America. It really undermines and discredits the whole concept of Christianity.”

For some evangelicals, he says, racism is “one of the areas of sin that need to be worked on.”

Citing the statistics on the rising number of hate crimes and on the gap in whites’ and blacks’ perceptions of racism, he claims the problem is getting worse.

Tarrants believes that the Trump era is the first time since the 1960s that people feel more emboldened to voice their racial prejudices, not less.

“What has happened now is that people on the extremes are feeling like the wind has shifted,” he warned. “It’s no longer at their face. Now it’s at their back. Their time is here.”