The Crystal Cathedral in Orange County, California, is one of America’s largest and most celebrated ecclesiastical buildings. At 60,000 square feet and designed by architect Philip Johnson, it was until recently the sanctuary of Robert H. Schuller, once one of the country’s most prominent and influential Christian ministers. In September 1980, when he dedicated the cathedral at an opening ceremony (“To the glory of man for the greater glory of God”), Schuller was at the height of his influence, preaching to a congregation of thousands in Orange County and reaching millions more worldwide via the Hour of Power, a weekly televised ministry program. Among the show’s annual highlights were “The Glory of Easter” and its companion production, “The Glory of Christmas,” multimillion-dollar dramatic extravaganzas staged inside the cathedral with a cast of professional actors, Hollywood-grade costumes, and live animals. The setting for the spectacles was a striking, soaring, light-filled structure justly praised by architecture critics. But it was not a cathedral. It was never consecrated by a religious denomination. The building is not even made of crystal, but rather 10,000 rectangular panes of glass. Like the much beloved, much pilloried Disneyland three miles to the northwest, the Crystal Cathedral is a monument to Americans’ inveterate ability to transform dominant cultural impulses—in this case, Christianity itself—into moneymaking enterprises that conquer the world.

But 2013 marked the end of an era. In June, Schuller’s evangelical Christian ministry, founded almost 60 years ago amid the suburbs of postwar Southern California, conducted its last worship service and filmed its last Hour of Power in the Crystal Cathedral. Hounded by creditors (including some of those Hollywood-grade costume and livestock suppliers), the ministry had declared bankruptcy three years earlier and last year sold the cathedral for $58 million to Orange County’s Catholic diocese. The diocese promptly announced plans to transform the 34-acre campus, which also includes notable ministry buildings by other name-brand architects, into Christ Cathedral, a spiritual home and civic showplace for the county’s surging population of more than 1.2 million Catholics, many of them immigrants from Latin America and Southeast Asia. The equipment facilitating Schuller’s elaborate stagecraft—lights, cameras, below-stage elevators, theater-style seating, an indoor reflecting pool—will be ripped out and replaced with a consecrated altar, bishop’s cathedra, baptismal font, and votive chapels dedicated to the Virgin of Guadalupe and other saints prominent in immigrant Catholics’ devotional lives. When the building reopens for worship in 2016, it will embody a transformation in the nation’s spiritual landscape that is only now beginning to be felt.

Just 10 years ago, evangelical Christianity appeared to be America’s dominant religious movement. Evangelicals, more theologically diverse and open to the secular world than their fundamentalist brethren, with whom they’re often confused, were on the march toward political power and cultural prominence. They had the largest churches, the most money, influential government lobbyists, and in the person of President George W. Bush, leadership of the free world itself. Indeed, even today most people continue to regard the United States as the great spiritual exception among developed nations: a country where advances in science and technology coexist with stubborn, and stubbornly conservative, religiosity. But the reality, largely unnoticed outside church circles, is that evangelicalism is not only in gradual decline but today stands poised at the edge of a demographic and cultural cliff. The most recent Pew Research Center survey of the nation’s religious attitudes, taken in 2012, found that just 19 percent of Americans identified themselves as white evangelical Protestants—five years earlier, 21 percent of Americans did so. Slightly more (19.6 percent) self-identified as unaffiliated with any religion at all, the first time that group has surpassed evangelicals. (It should be noted that surveying Americans’ faith lives is notoriously difficult, since answers vary according to how questions are phrased, and respondents often exaggerate their level of religious commitment. Pew is a nonpartisan research organization with a track record of producing reliable, in-depth studies of religion. Other equally respected surveys—Gallup, the General Social Survey—have reached conclusions about Christianity’s status in present-day America that agree with Pew’s in some respects and diverge in others.)

Secularization alone is not to blame for this change in American religiosity. Even half of those Americans who claim no religious affiliation profess belief in God or claim some sort of spiritual orientation. Other faiths, like Islam, perhaps the country’s fastest-growing religion, have had no problem attracting and maintaining worshippers. No, evangelicalism’s dilemma stems more from a change in American Christianity itself, a sense of creeping exhaustion with the popularizing, simplifying impulse evangelical luminaries such as Schuller once rode to success.

Prominent figures in the evangelical establishment have already begun sounding alarms. In particular, the Barna Group, an evangelical market research organization, has been issuing a steady stream of books and white papers documenting the erosion of support for evangelicalism, especially among young people. Contributions from worshippers 55 and older now account for almost two-thirds of evangelical churches’ income in the United States. A mere three percent of non-Christian Americans under 30 have a positive impression of evangelical Christianity, according to David Kinnaman, the Barna Group’s president. That’s down from 25 percent of baby boomers at a similar age. At present rates of attrition, two-thirds of evangelicals in their 20s will abandon church before they turn 30. “It’s the melting of the icebergs,” Kinnaman told me. Young people’s most common complaint, he said, is that churches are too focused on sexual issues and preoccupied with their own institutional development—in other words, he explained, “Christianity no longer looks like Jesus.”

A book making the rounds among evangelical pastors these days is called The Great Evangelical Recession. Written by John S. Dickerson, a former investigative journalist turned evangelical pastor, it chronicles in unsparing statistical detail how evangelical Christianity is hemorrhaging members, money, and influence. “The United States has shifted into a … post-Christian age,” he writes. “No one disputes this.”

Visible from nearby freeways, the 128-foot-tall Crystal Cathedral looms over Orange County’s landscape of low-rise tract houses, shopping centers, and manicured office parks. Up close, it resembles a giant, angular greenhouse. Glass panes, affixed to steel trusses by silicone-based glue, cover the entire exterior, glinting in the hazy Southern California sunshine and reflecting the landscaped grounds. Across a paved plaza from the cathedral are an older church sanctuary and an office tower designed in the 1960s by celebrated modernist architect Richard Neutra, and the so-called Welcoming Center, a performance and exhibition space completed in 2003 by Pritzker Prize–winning architect Richard Meier, known for his design of the Getty Center in Los Angeles. Adjacent to these buildings are a memorial garden and columbarium sunk like an amphitheater into the ground, and a 236-foot-tall mirrored glass bell tower, also designed by Philip Johnson.

The cathedral complex is an odd, sometimes startling juxtaposition of high and low culture. The three main buildings, though architecturally distinguished, bear no stylistic relation to one another and thus resemble ships from different eras run aground on a shoal. The light-filled interior of the cathedral, seen from ground level, feels more like a corporate convention hall than a religious sanctuary. Before the Catholic diocese began renovation in 2013, potted palms and ferns surrounded a raised stage. A reflecting pool ran the length of an aisle between rows of folding, padded theater seats. Banks of stage lights hung from the roof. Giant speakers flanked the stage. Outside, gaudy statues (“The Smiling Jesus,” “Christ With the Lost Sheep”) adorned the plaza, including a bronze replica of Jesus striding across a reflecting pool at the base of Neutra’s exacting, 13-story Tower of Hope. Amateur religious art donated by members of Schuller’s congregation hung in an exhibition gallery adjacent to the reflecting pool.

On a recent tour of the cathedral, Father Christopher Smith, the Catholic priest charged with supervising transformation of the complex into a Catholic worship space, did his best, but frequently failed, to be diplomatic about Schuller’s design sensibilities. “It was a beautiful campus,” he said. “It’s still beautiful. But it’s tired.” He pointed up toward the cathedral’s sloping glass roof. “We recaulked 1,500 panes of glass. We’re really trying to fix the leaks.” In its final years, Schuller’s cash-strapped ministry skimped on building maintenance.

Outside, on the plaza, the priest stopped beside a statue of children surrounding a beneficent Jesus. “Some of these are awful,” he remarked. Most, he said, would be removed during the diocese’s $53 million renovation. The diocese, taking its inspiration from the historic cathedrals of Europe, envisions the structure as something wholly different from Schuller’s ministerial showplace. “Traditionally, cathedrals are centers of art and culture,” Smith said. “We want it to be that.” He spoke of touring symphony orchestras playing in the sanctuary, academic and theological conferences in the Welcoming Center’s exquisitely spare meeting spaces, ecumenical worship services, art exhibits, the bustling cultural activity of a civic gathering place—something Orange County, built over decades with little central planning in car-mad Southern California, simply doesn’t have.

Born in Iowa in 1926 and educated at an evangelical seminary in Michigan, Schuller arrived in rapidly suburbanizing Orange County in 1955, the year Disneyland opened. Like other successful evangelical ministers before and after him, he quickly grasped the direction American society was moving and molded his ministry accordingly. He established a church not in a building but at a drive-in movie theater in the town of Garden Grove, which, following World War II, was rapidly transforming from an expanse of orange, walnut, and strawberry farms 30 miles south of Los Angeles into a grid of suburban neighborhoods home to 44,000 people. Five years after Schuller’s arrival, the newly incorporated city’s population had doubled. Many of those new residents attended Schuller’s church, where he preached atop a snack bar to rows of worshippers in their cars. In 1958, Schuller bought a parcel of land a few miles from the drive-in and commissioned Neutra, an émigré Austrian who had made his name designing glass-walled houses for wealthy Los Angelenos, to build a permanent home for what was then called the Garden Grove Community Church. Neutra’s modernist, rectangular worship hall was dedicated in 1961. Seven years later, the architect added the equally severe Tower of Hope. In 1980, by this time a pastoral celebrity known around the world, Schuller began preaching in the $18 million Crystal Cathedral.

Schuller, like Billy Graham and other name-brand evangelical ministers, led a mid-20th-century spiritual resurgence that corresponded with the birth and subsequent coming of age of America’s baby-boom generation. Even as older, inner-city mainline Protestant congregations withered in postwar America, suburban evangelical churches gained members when boomers, now having children of their own, began showing up in the late 1970s. A decade later, evangelical megachurches—some of the largest of which were in Orange County—were the dominant trend in American Christianity, growing in lockstep with the suburbs that gave them birth and set their spiritual tone.

The Christianity practiced in these suburban churches was not of the fire-and-brimstone variety. Evangelicals are far looser and more theologically diverse than Christian fundamentalists, who emerged in the late 19th century in reaction to the destabilizing effects of industrialization, the Civil War, and advances in science. Fundamentalism, especially the view that the Bible is inerrant in all of its teachings, has been steadily declining as a force in American Christianity for decades. Recent Barna Group research shows that just 38 percent of Christians—down from close to half two decades ago—regard the Bible as “totally accurate in all of the principles it teaches.” Evangelicals, by contrast, while acknowledging the authority of scripture, place greater emphasis on the believer’s personal relationship with Christ. They trace their roots in America to Jonathan Edwards, an 18th-century Massachusetts divine who paired Calvinistic theology with scholarship, evangelism, and spiritual conversion. The preeminence of conversion has produced huge variety and creativity in their outreach to nonbelievers. For nearly a century, evangelicals have been at the forefront of innovations in church music, worship style, architecture, and use of media to engage the non-Christian world.

Schuller was one of those innovators. His embrace of California car culture, his commissioning of high-profile architects, and his focus on televised spectacle were all efforts to wow, and woo, secular audiences. (Those approaches also fed Schuller’s ego, and their success his pocketbook.) The suburban style of evangelicalism Schuller pioneered was showmanlike and inspirational, emphasizing feel-good messages and entertaining worship services rather than liturgical tradition and theological complexity. Most other large evangelical churches have followed this pattern, with greater or lesser doses of commitment required of their worshippers. Christian traditionalists often assailed popular evangelical ministers for watering down the faith. But their flocks grew as baby boomers, accustomed to television and American plenitude, sought churches that matched their upwardly mobile, entertainment-oriented life styles.

Only with the social turbulence of the late 1960s—and particularly after the Supreme Court’s 1973 legalization of abortion—did evangelicals begin moving to the political right, merging with fundamentalists in a conservative Christian voting bloc—a rightward tilt that tracked with larger shifts in American culture. As the boomers’ youthful political activism evolved into the suburban libertarianism and mistrust of government that propelled Ronald Reagan into office, evangelical megachurches offered their own spiritual blend of social conservatism and entrepreneurial innovation. Pastors emulated the corporate managers who often filled their pews. They researched their audience, introduced new products, marketed their offerings, and measured success by growth in membership and budgets.

Schuller’s own Orange County was at the forefront of America’s plunge into entrepreneurial suburbanization. Explosive growth in the county during the 1950s and ’60s led in subsequent decades to the construction of sprawling planned communities. Heavily capitalized developers transformed the landscape into a manicured rebuke to America’s troubled inner cities. Their plans excluded the prevailing elements of urban design: high-rise buildings, mixed-use commercial districts, multifamily housing, and straight streets, which were thought to be easier for criminals to navigate. The county lured corporations with plush but safely bland office parks, and local governments kept taxes low and business regulations light. The result was a resounding success. Today, Orange County is an economic colossus with a 2012 GDP of $195 billion; per capita, its GDP is roughly the size of Singapore’s. Over the years, some portion of that wealth flowed into the evangelical churches, which molded themselves to suit the county’s mostly white-collar, affluent population.

But just as Orange County pioneered a new form of low-rise urbanism, it was also among the first places to experience the demographic consequences. All those planned communities—their well-paid inhabitants liked to eat out, their houses needed cleaning, and their lawns needed trimming. Beginning in the 1970s, migrants, mostly from Mexico, Central and South America, Southeast Asia, and Korea, began arriving to cook, clean, and mow. These immigrants and their families began taking over formerly all-white neighborhoods, principally in northern parts of the county, transforming the look and cultural fabric of those areas. Today, Orange County is one of the most ethnically, politically, and economically diverse places on the planet. Only 43 percent of its more than three million residents are white, and almost a third were born abroad.

Nowhere is this more visible than in the neighborhoods surrounding the Crystal Cathedral. Garden Grove, where Schuller once preached to young white homeowners in their cars, is now inhabited almost entirely by immigrants and their descendants. The adjacent city of Westminster is home to the world’s largest population of Vietnamese outside Vietnam. In another neighboring city, Santa Ana, 82 percent of the families speak at home a language other than English, primarily Spanish. These mostly poor residents cram several families into tract houses, work low-wage jobs, and reliably vote Democratic (the county’s registered voters are evenly split between Democrats and Republicans; Barack Obama won in 2008, Mitt Romney in 2012). They also gravitate not to evangelical megachurches like Schuller’s but to Catholic parishes, Buddhist temples, mosques, and storefront Pentecostal churches. The Islamic Society of Orange County, which owns a mosque, school, and mortuary five miles from the Crystal Cathedral, is one of America’s largest centers of Islamic worship. The Hsi Lai Temple in Hacienda Heights, a few miles north of Orange County, is the largest Buddhist temple in the United States. Orange County’s Catholic diocese is one of the nation’s largest and fastest growing.

This demographic shift, which experts predict will make the United States’ majority population nonwhite in roughly three decades, has not been kind to suburban evangelicalism. Young people in Orange County, no matter their ethnic or economic background, no longer view themselves as living in a suburban appendage of urban Los Angeles. The county is dense with Vietnamese pho joints, boba tea shops, Asian shopping malls, halal markets, Mexican swap meets, punk-rock nightclubs, and art galleries. Corporate-style megachurches seem bland by comparison. Several of them remain in Orange County, including the Rev. Rick Warren’s Saddleback Church, Mariners Church in the planned community of Irvine, and First Evangelical Free Church in Fullerton. But these are clustered in the county’s most affluent areas. None are growing rapidly anymore.

These days, young Christians in Orange County attend very different kinds of churches, some unrecognizable as churches at all. Laundry Love, a ministry in Santa Ana, is an ad hoc community of young Christians who gather monthly at various inner-city, coin-operated laundries and wash patrons’ clothes for free. The ministry is an offshoot of Newsong Church, a mostly Asian evangelical congregation founded nearly three decades ago by a pastor named Dave Gibbons, who sought to reach people like himself, mixed-race descendants of immigrants (his parents are white and Asian) who felt out of place in mainstream American society. Newsong now has branches in Thailand, England, Mexico, and India—all of which function like self-sustaining Christian communes oriented around humanitarian relief initiatives. Gibbons has emerged as one of a growing number of in-house critics of evangelical Christianity’s wholesale adoption of corporate American values. “The church has become involved in big business,” he told me by phone. “That’s why artists and creatives don’t want anything to do with church. What’s unique about how we’re trying to do things is we focus on people who aren’t like us. We don’t have to build our own brand.”

A decade ago, Newsong, with 4,000 members, was on its way to becoming America’s latest Asian megachurch. Unsettled by its relentless focus on growth, Gibbons abruptly changed course, rededicating Newsong to ministering in low-income neighborhoods and providing a haven for artists. More than a quarter of the congregation left. But now Gibbons’s move seems prescient. In the past decade, evangelical churches, especially in culturally diverse urban areas, have been forced to choose between adopting urban cultural values and extinction. “The megachurch was a baby-boomer suburban phenomenon that folks under 45 typically aren’t perpetuating,” says Ryan Bolger, who teaches contemporary Christianity at Fuller Theological Seminary in Pasadena. Young evangelicals “want to start communities in cafés, and this isn’t just whites. We’re starting to see with Koreans and Latinos a desire to move away from the churchiness of church, to be multicultural and in an urban context, church in the profane areas of life.”

At Epic Church, a 200-member, decade-old congregation in a northern part of Orange County populated mostly by Koreans and Hispanics, members gather for weekly worship in a rented office building but spend much of their time together working as tutors to low-income students at a nearby neighborhood center. “We haven’t been a church that understands ourselves as goods and services,” said Kevin Doi, Epic’s founder and pastor. The church welcomes gays, makes no overt effort to raise money from members, and regularly invites residents at a neighboring homeless shelter to its services. Doi said he has no long-range plan for his church and wouldn’t mind if it ceased functioning as an institution altogether. “We didn’t feel like our goal was to get people to come to our church,” he said. “We wanted to be present in the neighborhood, where we’re the guests.”

In a few years, perhaps a decade or two, religious America will catch up to Orange County’s present. There will be a shrinking number of evangelical megachurches, gradually aging and waning in influence. There will be numerous small, eclectic, multiethnic evangelical congregations whose emphasis on spiritual commitment and social service is unlikely to attract a large, mainstream following. And there will be surging numbers of immigrant Catholics, Pentecostals, and Muslims. The political influence of evangelicalism will decline. America will not become like Europe, where ossified state churches proved unable to compete against the inherently secularizing forces of market capitalism—and where immigrants’ faith expressions are often met with hostility. America will remain exceptionally religious. But traditional evangelical Christianity will no longer be a dominant presence in that religiosity.

Two years ago, in December 2011, yet another immigrant arrived in Orange County. Rob Bell migrated not from abroad but from Michigan, where he was a megachurch pastor and author who’d recently made the cover of Time and was about to be profiled in The New Yorker. Bell’s arrival, with his wife and three children, in the oceanfront city of Laguna Beach was tantamount to an escape. His spring 2011 book, Love Wins, the catalyst for the magazine stories, had ignited a firestorm in the world of evangelical Christianity. The book questioned the existence of hell and raised the possibility that all people, not just Christians, will be redeemed by God. Nothing in the book was theologically new; indeed, Bell never denied outright the reality of hell. But his book became a flashpoint in the ongoing debate over evangelicalism’s future. Younger, liberal evangelicals were for the book. Older, conservative evangelicals rejected it. In the midst of the debate, Bell, who had already tired of the institutional responsibilities of running his 10,000-member Mars Hill Bible Church in Grandville, Michigan, stepped down from leadership and lit out in semi-anonymity for the beach.

When I spoke to Bell earlier this year, he was still in the first flush of California love, waxing lyrical about the spirituality of surfing (he owns seven surfboards and arranges his schedule around the daily surf report). He was also at work on plans for a television talk show. Bell represents the new breed of young evangelicals who are, with gathering speed, reshaping and in some respects dissolving their movement. A decade ago, Bell was lionized in the evangelical world for blending the movement’s age-old formula (conservative theology; rapid, corporate-style growth) with hip new brains and style (sermons larded with quantum physics; a YouTube video series). Yet, like so many younger evangelicals, Bell grew disenchanted with church. By the time he wrote Love Wins, he was already fantasizing about Southern California, where he had attended graduate school. Bell doesn’t go to church in Laguna Beach. He and some friends from college have formed a quasi-intentional spiritual community, gathering in one anothers’ homes to worship and talk about faith.

“Evangelicals are good at whipping people up into a frenzy, and then you’re like, ‘What was that?’ ” Bell told me. “I was the pastor of a megachurch, and lots of people came, and I did book tours and interviews and films. That’s fine. But I’ll take seeing God every day, which is washing dishes with my kids and walking my dog and interacting with someone I just met.”

In other words, the future of the evangelical church as glimpsed from Orange County might be no church at all. Robert Schuller’s brand of worship might just turn out to be nothing more than a spiritual fad. As the generation that embraced it—middle-class, baby-boomer whites flocking to car-based suburbs—dies off, their spirituality dies with them. This is not to say that the church will go away. The Crystal Cathedral still stands. But its name is now Christ Cathedral. And Schuller’s vision of a glittery surface reflecting himself and the suburbs where he preached is gone.