Visiting houses of worship in the United States, you can't help but see empty pews, giving the impression that organized religion in the United States is in trouble.

Increasingly, those who study church attendance and related matters are doing the math: In a recent study that projects what faith in America might look like in 50 years, Pew Research Center found that the number of Americans who identify as religious, which has been shrinking for decades, will continue to decline as the number of those with no religion will continue to grow.

For Christianity, the nation's largest religious tradition, there's no mathematic model that predicts a reversal of fortunes.

Clearly, Christian leaders are worried, especially those of the evangelical persuasion, whose main goal is to spread the word and reach more people with the Christian message.

"This is the largest and fastest transformation of religion in American history," said Collin Hansen, vice president for content and editorial director for the Gospel Coalition, an evangelical group that produces resources for churches. "The demographics don't suggest any positive turn around the corner."

That reality led Hansen and his colleagues to launch the Keller Center for Cultural Apologetics, a new initiative designed to help pastors and other Christian leaders adapt to a "post-Christendom culture." Named for influential evangelical writer the Rev. Tim Keller, founder of Redeemer Presbyterian Church in New York City, the center hopes to support "a new generation of bold evangelists and effective apologists who will communicate the unchanging gospel for a changing world."

Hansen, author of a new biography on Keller, summed up the challenges facing churches this way in an online announcement about the new center: "Many of our neighbors view Christianity as yesterday's news but also as the source of today's problems."

That's far from how Christianity was seen in the past, at least in the United States and other Western cultures. In a video announcing the center's mission, Keller argues that those cultures not only had a positive view of Christianity, they also provided a basic vocabulary of the faith, along with an understanding of ideas like sin and salvation and the basic teachings of Jesus.

In that context, "evangelism was just connecting the dots," said Keller. If they wanted deeper spiritual answers, people came to church.

But today's churches can no longer rely on that cultural support. "What if you can't get them in the door?" Keller asks. "How do you win people to Christ in a post-Christian area? And the church does not have any idea how to do that."

Autumn Ridenour, one of two dozen experts named as fellows of the Keller Center, said she was drawn by the idea of offering "a thoughtful, Christ-centered alternative that considers emerging cultural issues with deep theological reflection, compassion, and neighbor love."

A professor of Christian ethics at Gordon Conwell Theological Seminary, she said the center wants to pair "the transformative work of the gospel with social action and a more global understanding of Christianity."

"I saw a connection between the ideas in The Keller Center in its desire to bring together various thinkers, pastors, and academicians and my own desire for gospel renewal and spiritual formation within the broader global church," she told RNS in an email.

The center's work will be informed by a national survey of people who have left churches, conducted in partnership with political scientists Ryan Burge, a Baptist pastor and professor at Eastern Illinois University, and professor Paul Djupe of Denison University, who both study the changing religious landscape. The findings of that study will be published in a forthcoming book, "The Great Dechurching," co-written by Keller Center staffer Michael Graham.

Hansen said he hopes the center will help churches create space where Christians and their neighbors can meet and build friendships.

The launch of the center reflects a larger concern among evangelicals about their ability to connect with Americans in the 21st century. Along with political polarization, exacerbated during the Trump presidency, and the growth of the so-called nones, who claim no religion, there's been a loss of faith in institutions, including organized religion.

Evangelical leaders are fighting back broadly, in efforts such as the billion-dollar "He Gets Us" ad campaign, which includes television commercials — including a pair planned for the Super Bowl — and billboards around the country that relate the life and teaching of Jesus to modern day.

Ed Stetzer, director of Wheaton College's Billy Graham Center, who consulted with the "He Gets Us" campaign, called the ads "pre-evangelism," establishing a familiarity with Jesus that pastors and other evangelists in the past could expect in nearly any American town or city.

"The more distant Christian memory becomes in culture, the more you will need apologetics centers and pre-evangelism ad campaigns, he said.

Stetzer said Keller's reputation for ministering in a secular urban setting makes him an apt model for the center that bears his name. "As the rest of the country becomes more like New York, they are going to want to hear from someone who has been in a similar situation and has been effective," he said.

Hansen said he hopes the center will help people see the scope of changes that churches are facing in the culture. The loss of faith in institutional religion, he said, affects congregations across the Christian spectrum.

"We need all hands on deck," he said. "We need to raise the awareness and urgency around this transformation."

© Religion News Service