(RNS) — After nearly 30 years, a public relations agency that has acted as a powerful gatekeeper for some of the most prominent Christian faith-based organizations is closing its doors.

Mark DeMoss, 56, announced in a letter to friends Tuesday (Jan. 15) he is closing his eponymous, Atlanta-based firm — which describes itself as the nation’s largest PR agency serving faith-based organizations and causes — at the end of March.

DeMoss has represented such institutions as the Museum of the Bible, Hillsong, campus ministry Cru, the Billy Graham Evangelistic Association and Samaritan’s Purse, headed by Graham’s son Franklin. The firm also has been connected with two influential megachurches — Willow Creek Community Church in suburban Chicago and Mars Hill Church in Seattle — helping both to navigate crises involving their prominent pastors.

That career, DeMoss wrote, has given him an “all-access pass to so much evangelical history.”

The American Bible Society, which has worked with the agency for nearly a decade, called its closing “a great loss for the Kingdom.”

“DeMoss has made tremendous impact on Global Bible Ministry for nearly three decades by supporting and giving lift to Bible ministry messages and mission,” American Bible Society President and CEO Roy Peterson said in an email to RNS.

DeMoss — who attends Passion City Church, an evangelical megachurch headed by Louie Giglio in Atlanta — received “clarity and affirmation” about the decision to close the firm in what he called a “season of reflection” after his diagnosis with cancer two years ago, according to the letter. (He since has been declared cancer-free.)

He also realized he was passionate about the “practice of public relations — not the business of PR,” and he wasn’t sure he had the ability or passion to reinvent the firm the way he said so many other agencies have done in the past few years, pivoting to digital marketing and advertising.

“A big factor was the world has changed so much, communications has changed so much and the PR industry has changed so much that successful PR firms are reinventing themselves. They’re changing their business models,” he told Religion News Service. “I don’t think I know how to do that.”

Mark DeMoss, senior adviser to the Mitt Romney presidential campaign, speaks on a panel about faith outreach by both campaigns during the Religion Newswriters Conference in Bethesda, Md., on Oct. 5, 2012. RNS photo by Sally Morrow

DeMoss also has hinted at disenchantment with the country’s increasingly polarized political climate and its impact on evangelicalism.

In 2016, he stepped down from the board of trustees at Liberty University after Liberty President Jerry Falwell Jr. endorsed Donald Trump for president, calling the insults and bullying of the Trump campaign a rejection of the values promoted by Liberty founder Jerry Falwell Sr. and the university.

DeMoss disagreed about the “appropriateness” of the endorsement, but, he said at the time, “I hope we have not ‘fallen out’ over this matter. I am a Liberty graduate and have been associated with the school for nearly 40 years. Despite our differences on this endorsement, Jerry and I share a love for Liberty University.”

In the 1980s and early ’90s, DeMoss spent eight years as chief of staff to Falwell Sr., who, The Washington Post has said, he considered to be a second father.

DeMoss was a senior adviser to Mitt Romney during his unsuccessful presidential runs and led evangelical efforts to get out the vote for Romney.

And DeMoss encouraged religious leaders to do their part to calm the political rhetoric, launching an online forum called The Civility Project with Democratic consultant Lanny Davis ahead of President Obama’s first inauguration in 2009. The project had three principles: to be civil in public discourse, respect those with whom you disagree and stand against incivility.

“Many Christians like to call ourselves followers of Christ,” he said at the time. “I can’t be a follower of Christ if I’m shouting at you or interrupting your meeting, and I certainly don’t look like one when I do that.”

DeMoss has not said he is retiring. Instead, he wrote in his letter, he is looking forward to a period of rest like the sabbaticals he has given employees at his firm but never taken himself. He plans to spend that time reading, studying, praying, seeking counsel and perhaps writing.

(RNS national reporter Adelle M. Banks contributed to this report.)