In 2001, Alan Chambers was hired as the president of the world’s largest ex-gay ministry, Exodus International. That same year, U.S. Surgeon General David Satcher issued a report that stated, “there is no valid evidence showing that sexual orientation can be changed.”

Like most conservative Christian leaders at the time, Chambers considered the countercultural nature of his work a point of pride. During the latter part of the 20th century, Exodus and similar conservative groups promoted the idea that gay people could—and should try to—become straight. Ex-gay leaders traveled to churches and appeared on television news programs citing a litany of examples of happily married “former homosexuals” to demonstrate that sexual orientation is a choice and that change is possible.

But Chambers would undergo a radical change of heart. In 2013, he publicly apologized to the LGBT community for the “pain and hurt” Exodus had caused and announced that the ministry was permanently shutting down. Chambers’s decision effectively delivered the deathblow to the beleaguered ex-gay movement. And his story of transformation, detailed in a new memoir, My Exodus: From Fear to Grace with a foreword by CNN’s Lisa Ling, will likely resonate with many traditionalists who are searching for new ways to think about LGBT issues.

Chambers, 43, was raised by an ex-military father in a Southern Baptist home and realized he was attracted to other males at a young age. Most of his early sexual encounters with men were anonymous, which bred in him a deep self-hatred. At 19, he connected with an Exodus-affiliated ministry where he hoped to rid himself of same-sex attraction once and for all.

While the ministry did not make Chambers straight, he claims that it saved his life and many others because it provided a “safe space for many” to talk about their sexuality. At the time, there was no national network for LGBT Christians and most churches were not places of sexual transparency. But, he says, Exodus’s emphasis on “change” made it “fatally flawed.”

In 1998, Chambers married his wife, Leslie, with whom he adopted two children. In My Exodus, he recounts his inability to consummate the union for eight months, but he says their sex life is now “good.”

“While many relationships are built on sex, ours just includes sex,” Chambers says. “We love it and value it because we worked hard for it.”

As a former Exodus participant who once lived a “gay lifestyle” but was able to achieve a successful straight marriage, Chambers was the perfect candidate to lead the organization. And by 2001, Exodus needed all the help it could get.

At its peak, Exodus International had an annual operating budget of more than $1 million, had 25 employees, and served as an umbrella organization for more than 400 local ministries across 17 countries. But over the years since its founding in 1976, many of the leaders Exodus’ touted as success stories had become cautionary tales instead.

Cofounder Michael Bussee left the group in 1979 and entered a relationship with another Exodus leader, Gary Cooper. Bussee would later admit, “I never saw one of our members or other Exodus leaders or other Exodus members become heterosexual, so deep down I knew that it wasn’t true.” Throughout the 1980s and ‘90s, many former Exodus members became vocal critics of the ministry, claiming it had caused them psychological distress. And in September 2000, Exodus’s chairman John Paulk was photographed cruising for men at a gay bar in Washington, D.C. He was ousted from his position and later confessed, “I do not believe that reparative therapy changes sexual orientation; in fact, it does great harm to many people.”

The movement traditionalists believed would be their saving grace in the fight against LGBT rights was quickly becoming their Achilles’ heel.

Being chosen to lead Exodus in 2001 was like becoming the ex-gay Pope following the Catholic sex-abuse scandals. The ministry’s board knew it could not survive another public scandal, so it questioned Chambers rigorously before deciding to hire him. During the interview process, Chambers recalls a board member asking him what success would look like under his leadership. He replied, “It looks like Exodus going out of business because the church is doing its job.”

Chambers words would later seem prophetic, but he first needed to travel a long road. In 2005, he called homosexuality “one of the many evils this world has to offer.” And in 2006, he lobbied for a constitutional amendment banning gay marriage. But Chambers admits that during the same year his thinking began to evolve.

“As I heard more stories and evaluated my own realities,” Chambers said, “I realized change in orientation was not possible or happening.”

Though the ex-gay leader was stewing on the inside, he seemed as resolute as ever on the outside. He advocated for California’s Proposition 8, which sought to ban gay marriage in the state. In 2009, he published a book called Leaving Homosexuality: A Practical Guide for Men and Women Looking for a Way Out. He admits to immediately regretting the book’s title and some of its content.

Chambers’s thinking continued morphing until his dramatic announcement that the ministry would shut down in 2013: “Exodus is an institution in the conservative Christian world, but we’ve ceased to be a living, breathing organism. For quite some time, we’ve been imprisoned in a worldview that’s neither honoring toward our fellow human beings, nor biblical.”

By this point, the ex-gay movement was already in shambles. A 2013 Pew Research poll showed that only 36 percent of Americans believe a gay or lesbian person’s orientation can be changed. As Satcher reported, modern science had delivered crushing blows to the ex-gay movement with peer-reviewed research showing that its ideology was bunk. And a national movement to ban reparative therapy for minors was taking shape and had already been successful in several states.

The closing of Exodus International became the “tipping point” in conservative Christians’ conversations about the nature of sexual orientation. Today, even top Southern Baptist leaders have denounced ex-gay therapy, and the school newspaper for the Jerry Falwell-founded Liberty University has editorialized against it.

“Shutting down Exodus dealt a fatal blow to the whole idea that orientation can be changed and that God somehow loves you more because of the choices you make,” Chambers says. “Some ministries still promote this idea, but they are not going to achieve the same level of success that Exodus had. That position is more of a minority than it has ever been.”

The release of Chambers’s memoir this month marks another step in the leader’s evolution. He has voiced his support for President Obama’s effort to ban orientation-change therapies for minors and celebrated the Supreme Court’s decision to legalize gay marriage. And now he even admits that he believes committed, monogamous same-sex relationships can be holy.

“I look at gay and lesbian people who are in committed relationships and I believe they can reflect the image of God,” Chambers says. “That belief has continued to evolve, but heterosexuals don’t have a corner on the market of healthy, holy relationships.”

While many culture-warring conservatives will undoubtedly see Chamber’s openness as a cowardly capitulation, others will call him courageous. The former ex-gay leader chooses to focus on just being honest, instead. As he said in a chapter intended for his memoir but cut by the publisher, “Every part of my life, all of my compartmentalization is reconciled. My message and story are no longer different depending on the group to whom I’m speaking.”

Chambers describes his current sexual orientation as “complicated.” While he is still attracted to men, he also says that he and Leslie have a healthy marriage with a robust sex life. But he no longer claims that every person with same-sex attraction should follow his path.

“For those who cannot reconcile their faith and sexuality, they can be affirmed in their choice of celibacy and devote their lives to causes more life giving than ‘ridding themselves of the demon homosexuality,’” Chambers says. “And the gay Christian community can be affirmed in who they already are: beloved.”