In 1999, I asked Michael Novak, the great scholar of religion and public affairs, to name the one book published after 1950 that most influenced how serious-minded people think about religion. Normally circumspect and slow to speak, Novak answered instantly: Harvey Cox’s The Secular City (1965). Cox, who taught at Harvard Divinity School, was a liberal Baptist theologian. In The Secular City, he predicted that religion would recede as more people came to reside in demographically and culturally diverse cities. Cox was none too broken up about this forecast. “[T]he cosmopolitan confrontations of city living,” he argued, would expose “the myths and traditions men once thought were unquestionable.” This global “secularization” would bring about “the dispelling of all closed world views, the breaking of all supernatural myths and sacred symbols.”

The famous April 8, 1966, edition of Time—whose cover asked, “Is God Dead?”—featured Cox and other, still more radical theologians. They were accompanied by sociologists foretelling a death of religion to go with the death of God—including Peter L. Berger, an eminent Austrian-born sociologist who taught at several American universities. In his 1967 classic, The Sacred Canopy, Berger reckoned that urbanization, industrialization, technological innovation, and other modernizing forces would soon secularize modern society altogether. Neither Cox nor Berger was a Marxist, but the theory that a more urban world would be a less religious one echoed Karl Marx’s prophesies about religion’s certain demise. In The Communist Manifesto, Marx and his collaborator Friedrich Engels theorized that, because capitalism had “greatly increased the urban population as compared with the rural,” it had already “rescued a considerable portion of the population from the idiocy of rural life”—religion included. With socialist regimes to finish the job, the proletariat’s future would be atheist ever after.

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But a funny thing happened on the way to global secularization: namely, it didn’t happen. In 1996, writing in the National Interest, Berger flatly acknowledged that the secularization theory of the 1950s and 1960s had been “essentially mistaken.” What happened instead was what Berger, in the title of a 1999 edited volume, called The Desecularization of the World. In 2006, at the Pew Forum’s biannual Faith Angle Conference on religion, politics, and public life, Berger referred to our age as one of “overwhelming religious globalization.”

Europe is the one place where secularization theory has been vindicated. By the mid-2000s, only about one in 20 adults in the United Kingdom attended church on a regular basis. In Rome and several other European cities, Catholicism continued to shape local culture yet failed to attract many actual practitioners. But just about everywhere else on the planet where religious profession and practice were not outlawed outright, they were stable or spreading at the beginning of this millennium. For example, in The Next Christendom (2002) and The New Faces of Christianity (2006), Philip Jenkins, then a Penn State scholar, showed how Catholicism and orthodox Christian sects had grown by leaps and bounds in the southern hemisphere since the 1960s.

Today, the prospects for religion remain rosy worldwide. Several 2015 reports by Pew Research Center analysts predict that between 2010 and 2050, the Christian population will increase from about 531 million to 666 million in Latin America and the Caribbean, and double from about 517 million to 1.1 billion in sub-Saharan Africa. Globally, the “religiously unaffiliated”—self-identified atheists, agnostics, and those who say their religion is “nothing in particular”—were 16.4% of the world’s population in 2010 but will decline to 13.2% by 2050. Meanwhile, the total number of religiously unaffiliated people worldwide (1.2 billion) will be about equal to the number of Christians in sub-Saharan Africa alone (1.1 billion). Contra Marx, urbanization has not secularized the world—if anything, it has helped to do the opposite. Over the last six decades, the percentage of people living in urban areas has increased on every continent. But in most places, the proportion of people disavowing or ditching religious commitments has not increased, while that of people following a faith has remained steady or risen. Based on data from more than 2,500 national censuses, large-scale surveys, and more, the Pew-Templeton Global Religious Futures Project estimates that in 2050 the world will be home to about 2.9 billion Christians, 2.8 billion Muslims, 1.4 billion Hindus, 1.2 billion religiously unaffiliated individuals, and 1 billion people of other faiths. Outside China, more than 90% of the citified world’s people will be religiously affiliated. So for God’s sake, isn’t it time to declare secularization theory dead?

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Not so fast. In Secular Surge: A New Fault Line in American Politics, three of the most widely respected empirical researchers in the field of social science—Notre Dame’s David E. Campbell and Geoffrey C. Layman, and the University of Akron, Ohio’s John C. Green—offer a brilliantly researched and carefully reasoned argument for reconsidering secularization theory, based on their groundbreaking research in the United States. In the end, though, they do not succeed in resurrecting the theory.

Until now, only secularization diehards have dared to treat highly religious modern America as anything other than a bedeviling exception to the global secularization rule. The scholarly consensus on religion in America has remained pretty much where Berger, who died in 2017, left it. In a 2011 interview with BU, the Boston University magazine, Berger reprised his famous quip: India is the world’s most religious nation, Sweden is among its least religious, and “America is a country of Indians with a Swedish elite.” He added that “many culture war issues have to do with the Indians becoming increasingly pissed off at the Swedes.”

Secular Surge, however, suggests that now the increasingly numerous and well-organized Swedes have grown pissed off by “over forty years” of “stridency” from the Indians on the “New Christian Right.” The authors conducted three controlled experiments, which they summarize in the sixth of their 11 data-rich chapters. From this new evidence, it seems clear that “disaffiliation from a religious identity (i.e., the rise of the Nones), is caused by a backlash to politicized religion, especially the Religious Right.” This has led to “the emergence of Secularists as a political force to be reckoned with.”

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But how many “Secularists,” and measured how? To paraphrase humorist Garrison Keillor, if you think sitting in a church makes someone religious, you must think standing in a garage makes someone a car. Most surveys define secularism as “the absence of religiosity” (what people don’t believe), or else they measure binary behavior like whether or not someone goes to church. Secular Surge combines “new measures of personal secularism” (i.e., questions about what people do believe) with data on “card-carrying Secularists” like those in the American Humanist Association (AHA) and on delegates to national and state political conventions.

In 2019, the Pew Research Center pegged 26% of Americans as religiously unaffiliated, or “Nones” for short: 4% atheists, 5% agnostics, and 17% who describe their religion as “nothing in particular.” Secular Surge digs deeper, parsing multiple national datasets as well as the authors’ own 2017 “Secular America Studies” (SAS) survey. The results indicate that about 36% of Americans are Nones: 5.7% atheists, 6% agnostics, and 24.7% “nothing in particular.” But not all Nones are “Secularists.” To be counted as a Secularist, one must not only claim no particular faith, doubt or deny the existence of God, and be otherwise religiously indifferent or unaffiliated. One must also affirmatively “believe in scientific naturalism, rationalism, humanism, or freethinking” and hold other views that would make one feel at home in “secular organizations” like those that are now growing all across the nation—from old ones like the AHA, founded in 1941, to newer ones like the Secular Coalition for America, founded in 2002.

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Thus measured, about 28% of Americans are Secularists. That finding amply justifies the core claim of Secular Surge: Americans are far more secular than has hitherto been understood. The authors take care to make clear that most Secularists are not “hostile to religion”: only a third of Secularists agree that “individuals are better off without religion in their lives.” No less importantly, the book also shows that there are many Americans for whom secular values and religious observance overlap. Secularism as defined by the authors means both disbelieving in God and affirmatively believing in values such as rationalism and humanism. But there is no inherent reason why those two characteristics must go together—it is perfectly possible to mix and match religion with secular values. Thus the authors identify a category of “Religionists,” whose beliefs and behaviors are quite strongly faith-centered—37% of Americans fit that description. But 18% of Americans are “Non-Religionists,” meaning they believe neither in God nor in secular values. Another 16% are “Religious Secularists,” who practice religion but affirm the values defined by the authors as secular. This includes a third of biologists, chemists, and other natural scientists, who in a 2009 Pew Research Center survey said they “believe in God.”

The authors use their novel statistical findings to make two claims about American politics. The first is that a “deep and durable” divide will result in an ultra-polarized “confessional party system” that pits Secularist Democrats against Religionist Republicans, “perhaps with Religious Secularists representing a new kind of swing voter.” But, as suggested by much of the book’s own data, that fault line is old news. The second claim is more timely and concerns intra-party, not inter-party, conflict: “secularism is at the very heart” of realignment within the parties, and in particular of “battles for the soul of the Democratic party.” Secularists are now “ascendant in the Democratic party,” and they increasingly “prioritize ideological goals,” reject “calls for intraparty harmony and compromise,” and “zealously oppose compromise with the GOP.” A secular-religious storm is brewing: “Democratic Secularists are mostly white and mostly well-educated.” They “may attract new support from well-educated whites, but threaten the party’s long-time backing from working-class and minority voters.”

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For several reasons, I would bet against traditional Democratic base voters getting steamrolled by Secularists, and I would bet the house on Americans remaining a predominantly religious people for decades to come. First, as Campbell, Layman, and Green note, “nonbelief in God” remains “a political nonstarter” in both parties. Indeed, the most loyal Democratic base constituency is black Americans, 97% of whom “believe in God or a higher power,” according to a March 2021 Pew report. So do 97% of all religiously affiliated adults and 72% of all religiously unaffiliated adults. Even major tragedies steeped in partisan politics do not shake most Americans’ faith. For example, a Pew report released in January 2021 indicated that, by a 7 to 1 margin, Americans who say their own faith has been strengthened as a result of the coronavirus outbreak (28%) outnumber those who say it has made their faith weaker (4%).

Second, the authors speculate about the “birth of a Secular Left analogous to the Religious Right,” but they have “reason to think that secularism will remain inchoate and thus politically ineffectual.” Amen, but only if the Democratic Party’s faith-friendly majority pushes back. In 2008, I joined clergy and other leaders, including other “pro-life, pro-family, and pro-poor” Democrats, as a speaker at the 2008 Democratic National Convention’s “Faith Caucus.” The ballroom was so full of people and energy that it scared the hell out of the convention’s anti-religious zealots. Unfortunately, those zealots currently hold sway in the party, and they made sure nothing similar happened again in 2012, 2016, or 2020. They also scrubbed all talk of God from the party’s platforms. But look for 2024 to be a year when the party’s more moderate and religious constituents have their say, show up, and pray out loud.

Third, America’s religious individuals and institutions are enormously civic-minded in ways that tangibly benefit people of all faiths and none. In a 2001 report titled Better Together, I joined Harvard University’s Robert D. Putnam in documenting how the nation’s churches, synagogues, mosques, and other faith-based organizations “build and sustain more social capital…than any other type of institutions in America,” whether “measured by association memberships, philanthropy, or volunteering.” In stark contrast, as Secular Surge notes, Secularists and their organizations “specialize in politics”—in fact, Secularists do so little by way of “nonpolitical engagement” that the authors are obliged to caution against damning them as “civic deadbeats.”

Fourth, no miracles are needed to forge what Campbell, Layman, and Green call “a coalition of both Secularists and Religionists—emphasizing what brings them together instead of what pulls them apart.” Over the past quarter of a century, I’ve seen the beginnings of such an alliance take shape in literacy programs, homeless shelters, and more. For example, in 2001, President George W. Bush partnered with Philadelphia’s Mayor John F. Street, a black Seventh-day Adventist and a Democrat, to spotlight a mentoring program for the children of prisoners. That program was jointly supported by everyone from staunchly religious to strictly secular politicians, business leaders, foundation executives, and others. It has now served more than 350,000 children.

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Finally, the worst religion-related political polarization is as often inter- or intra-religious as it is between Religionists and Secularists. America is no stranger to all types of sectarianism. It has overcome them all—even the rabidly anti-immigrant, anti-Catholic politics that roiled the late 19th and early 20th centuries. For that, we should thank James Madison, who saw it all coming. In The Federalist, Madison acknowledged that Americans display a “zeal for different opinions concerning religion” and prescribed fostering a “multiplicity of sects” as the surest way to secure both civil peace and religious rights. Madison’s system survived the telegraph, plane travel, the radio, and television; it will survive the internet and social media, too. Around the world, religion continues to flourish when free, to persist even when persecuted, and to draw inspiration from America—a republic where Secularists and their sects, God bless them, will strive and thrive alongside the robustly religious for many decades to come.