Though giving to religion in the U.S. topped $100 billion in 2010—putting it at nearly 1 percent of GDP—no monthly index charts the nation’s leading religious indicators. Even the Census Bureau, the nation’s most comprehensive data-gathering enterprise, avoids collecting basic information about religion. No constitutional provision bars the collection of such information, but the government has long hesitated to intrude in the affairs of religious bodies. So most of what we know about religion in America is based on what individuals and groups reveal voluntarily to independent researchers. Fortunately, a small number of public foundations, most notably Lilly Endowment, the John M. Templeton Foundation and the Pew Charitable Trusts, continue to fund basic research on the state of American religion.

One of the most comprehensive recent surveys of American religious participation was reported in 2008 by the Pew Forum on Religion & Public Life. The survey included over 35,000 respondents, making it possible to present detailed demographic and attitudinal data on large and small religious communities.

The Pew report notes that the American religious landscape is increasingly fluid and competitive. Fully 28 percent of Americans have changed their religious affiliation since childhood, a percentage that rises to 44 percent when interdenominational “switchers” within Protestantism are included. The ranks of the religiously unaffiliated are now 16 percent of American adults and fully a quarter of those age 18 to 29.

Protestantism continues to lose market share and will soon be a minority religious tradition. It remains fragmented: 26 percent of Americans identify with evangelical Protestant denominations, 18 percent with mainline or oldline Protestant churches, and 7 percent belong to historic black churches.

Baylor University’s Institute for Studies of Religion is emerging as another significant resource on religious change and demography. ISR has directed three large national surveys conducted by the Gallup Organization. The latest, published in September 2011, The Values and Beliefs of the American Public, looks especially at health and religiosity, the relationship between entrepreneurship/work and religion, religion and the American ethos (individualism), and the relation between religious beliefs and views on politics and same-sex marriage.

The researchers probe believers by testing their response to the statement “God has a plan for me.” Those who strongly agree with this statement have lower income and educational levels than other Americans and are more likely to believe that the U.S. economic system is fair and does not require governmental intervention. They tend to view government as too intrusive, to believe that anything is possible through hard work and that healthy people don’t deserve unemployment benefits. These findings illuminate some voter dynamics evident in the 2012 presidential race.

Much of the Baylor report explores differences between liberals, moderates and conservatives. Not many surprises here. Self-described liberals, we learn, are less likely than self-described conservatives to say they believe in ultimate truth but more likely to believe that all religions worship the same God.

The most interesting portions of the Baylor study deal with attitudes toward homosexuality and civil liberties for gays and lesbians. The researchers find that a majority (65 percent) of Americans now favor same-sex civil unions and that 47 percent favor gay marriage and oppose laws prohibiting it. Attitudes toward gay civil liberties are major points of division between liberals and conservatives: 70 percent of conservatives support a law banning gay marriage, while only 14 percent of liberals do so.

The past two decades have seen two important methodological breakthroughs that have improved our ability to observe trends and changes in congregations. One advance has been through the work of Faith Communities Today, a project initiated in the late 1990s at Hartford Seminary’s Institute for Religion Research. The project brings together representatives from most of the larger Christian communions and from Jewish and Muslim religious bodies. Each of more than 20 groups draws a representative sample of its member congregations and administers a common questionnaire. Four national surveys have been conducted, and over the course of the project 28,789 randomly selected congregations have participated.

Two FACT reports were released in 2011. In A Decade of Change in American Congregations 2000-2010, project director David A. Roozen reports that the past decade has shown “a slow, overall erosion of the strength of America’s congregations.” The report documents a steep drop in congregations’ financial health and continuing high levels of conflict, along with aging memberships. It also shows that congregations are increasing their interaction across faith lines and are giving more attention to innovative worship practices. Moreover, it points to the relative vitality of congregations that serve racial minorities and immigrants.

FACT underscores the aging of mainline congregations and the relative absence of young adults in these churches. Roozen reports that persons age 65 or older constitute more than a third of the members in a majority of old-line Protestant congregations, and the same is true in almost a quarter (23 percent) of evangelical Protestant churches.

In our 1987 book American Mainline Religion, Wade Clark Roof and I suggested that in the future “liberals will represent a smaller and smaller share of the Protestant movement,” and that prediction seems safe in light of recent data. Says Roozen: “The age structure of liberal Protestantism suggests a rising death rate that, given the relatively few members of childbearing age, is unlikely to be offset by births.” Demography may not be destiny for mainline churches, but it continues to present daunting challenges.

Another FACT report released in 2011 examines congregational growth and decline. In FACTS on Growth: 2010, C. Kirk Hadaway weights his sample to make it representative of the entire landscape of congregations: 23.8 percent are mainline Protestant, 55 percent conservative Protestant, 6.4 percent black Protestant, 6.4 percent Roman Catholic and Orthodox, 11.2 percent other Christian and 3.6 percent non-Christian. Hadaway then divides congregations into five growth categories, ranging from those showing severe decline to those recording greatest growth, using a scale that measures percentage change in worship attendance and net change in worship attendance between 2005 and 2010.

He finds “greatest growth” congregations are most likely located in the South and in communities experiencing population growth. Also growing are younger congregations (those organized in the past 15 years), those with a majority of members from racial minority backgrounds and those that use a language other than English. Congregations in which a majority of members are age 50 or older are very unlikely to grow. One surprising finding is that downtown or central city congregations are more likely to be growing than those in newer suburban locations.

Several attributes of the internal life of congregations are strongly associated with growth in worship attendance. These traits are: a clear sense of the congregation’s mission and purpose; a sense that the congregation is spiritually vital and alive; a sense that the church is “a moral beacon in our community”; and a willingness to meet new challenges. Serious internal conflict is a very strong predictor of congregational decline.

Hadaway also looks at a number of dimensions of congregational identity and their relationship to growth. Denominational family continues to make a difference: 43 percent of conservative Protestant congregations are growing, compared to 33 percent of non-Christian congregations, 29 percent of Catholic/Orthodox congregations, 25 percent of other Christian groups and 19 percent of mainline Protestant congregations.

He cautions, however, against concluding that growth is directly related to theological orientation. “In fact,” he notes, “the proportion of congregations growing is highest on the two end points: very conservative congregations and very liberal congregations (with growth rates of 39 percent and 35 percent respectively).”

A direct comparison of the theological orientation of mainline and conservative Protestant congregations reveals almost no relationship between theological conservatism and congregational growth. To be sure, conservative Protestant congregations tend to grow more than mainline congregations, but Hadaway suggests that “it is not theological conservatism per se that leads to growth, but rather something intrinsic to the evangelical/conservative Christian family and its constituency.” He goes on to say that “the weakness of the mainline churches probably has more to do with pervasive problems among the mainline constituency (such as lower levels of church involvement, competing demands for time, and lower birth rates) than it does with their more moderate theology.”

A second congregation-based project was conducted by sociologist Mark Chaves of Duke University. Chaves worked with the National Opinion Research Corporation at the University of Chicago to draw a sample of the congregations with which participants in the 1998 General Social Survey of the U.S. population were affiliated. In other words, Chaves took a look at some of the congregations in which a representative sample of American adults participate. American Religion: Contemporary Trends draws on the General Social Survey and the National Congregations Study to paint a big-picture portrait of changes in American religion since 1972.

Chaves takes a cautious approach, focusing on important trends that are both interesting and well documented. Chaves insists—rightly, I think—that one cannot conclude either that “American religiosity is experiencing a dramatic resurgence” or that it has declined dramatically.

Chaves points to several major trends, most of which are familiar. Americans are becoming more diverse religiously and more tolerant and appreciative of religious difference. Religious beliefs are surprisingly stable, but spirituality is more diffuse than it once was; most of those who think of themselves as spiritual also think of themselves as religious, but for a minority the much commented-upon distinction between the two is real. Changes in religious involvement are hard to pin down, because people tend to overstate their religious participation. Chaves tentatively states: “We can see clearly enough to conclude that religious involvement unambiguously is not increasing.”

Participation in a congregation, Chaves maintains, is still the most common form of religious involvement. Religious leadership is changing and has become a less attractive career choice. Public confidence in religious leaders has declined precipitously.

Chaves points out that liberal Protestantism is the only major religious group to “have experienced significant, sustained decline in recent decades.” Religious involvement is more closely linked to conservative social attitudes than in earlier times. At the same time, “as a set of ideas, religious liberalism steadily has gained ground in the United States, whatever the fate of the denominations most closely associated with it.”

These recent studies reveal the significant changes that have taken place in American religion over the past several decades. Rising costs at all levels, declining memberships, lower levels of denominational loyalty and competition for philanthropic dollars have combined to create a financial crisis for most organized religious communities. Some of the healthiest organizations (such as many colleges and hospitals) are the ones furthest removed from ecclesiastical control.

The crisis that emerges from these snapshots of religious life is twofold. The first is the growing inability of many mainline institutions to maintain themselves. The second crisis may be more important in the long run: the absence of resources for building new institutions to meet current and future needs.

Across the denominational spectrum, religions have fought to maintain the institutional forms and practices that were put in place in the 19th century to meet the needs of an expanding population. Religious groups knew who “their” people were, and the institutions they built were shaped to meet their community’s needs. For example, Lutherans built schools and colleges to prepare immigrant Germans, Swedes and Norwegians for careers on the frontier; Presbyterians started seminaries to prepare learned clergy for their congregations; Catholics and Jews founded hospitals to provide health care for their people.

Over time each group developed remarkably similar patterns of connecting their local, regional and national constituencies in order to carry out their particular mission. Formal and informal clusters of denominational groups came into being to express similar theological, ethnic and mission commitments. Most of those institutions still exist in some form, albeit in slimmed-down versions.

In 1976, when I started my first full-time position as a researcher in one of the national agencies of the United Church of Christ, my boss told me that my job was “to figure out what is going on in the United States and what it means for the church’s mission.” I didn’t realize at the time how important it would be to link these two questions. The most effective leaders I have known are those who can connect their descriptions of reality with practical agendas for action.

Social research such as the studies summarized here does not spell out an agenda, but it can inform one. The sustainability of the mainline Protestant traditions in particular depends on their ability to answer some huge questions. Can these traditions speak to the religious yearnings of younger Americans? Will they invest in reaching out to the new populations, especially to immigrants? Can they articulate a compelling message to population groups whose principal exposure to Jesus Christ and to Christianity has flowed through mostly conservative channels? Will they be able to identify, prepare and support a new generation of leaders who can help shape new forms of congregating that will be sustainable?

The challenges call for more than technical fixes. They are what Ron Heifetz has called “adaptive challenges.” The last thing American faith communities need is another round of programmatic efforts to reverse declines. These haven’t worked because they haven’t addressed the fundamental changes that are taking place in the broader culture.

A new poll from Virginia, a key swing state, suggests that evangelicals will help put Mitt Romney in the White House this November.

It has become a truism in recent years that evangelicals are critical to our national elections. As New York Times reporter Erik Eckholm pointed out on April 14, evangelicals accounted for nearly one-fourth of all ballots cast in recent presidential elections. Their lukewarm support for John McCain in 2008—with many staying home on Election Day and upwards of 30 percent of their 18-29 year-olds casting votes for Obama (Greenberg Quinlan Rosner Research)—helped give the White House to the Democrats.

Republicans have feared that Romney’s Mormonism will mean even fewer evangelical votes for their candidate in November. They cite a November 2011 Pew Forum poll that found 15 percent of evangelicals saying they would refuse to vote for Romney simply because he is a Mormon.

Of course, McCain in 2008 won 74 percent of the white evangelical vote, and still lost. But several things are different this time around. Even a slight increase in the percentage of evangelicals at the polls will have significant consequences. The Baylor Religion Survey estimates that evangelicals are now one-third of the population, or 100 million people. An increase of only 1 percent at the polls—a million voters—most likely means a two-to-one advantage for Romney among those million votes, which could tip several key states against Obama.

Now there is fresh evidence that evangelicals in swing states are more numerous than ever, and prefer Romney to Obama by a wide margin. A March 26-April 9 poll of Virginia residents conducted by the Institute for Policy and Opinion Research at Roanoke College found that 58 percent of the Virginia population is evangelical, and white evangelicals prefer Romney by a 36-point spread (65 percent to 29 percent).

Not surprisingly, Virginia evangelicals are ambivalent about Romney’s religion. More than twice as many evangelicals as non-evangelicals in Virginia (37 percent to 16 percent) think Mormons are not Christians, and 74 percent of the evangelicals (vs. 61 percent of non-evangelicals) say Mormonism is “very different” from their own faith. Sixty-one per cent of evangelicals think the Mormon religion is not Christian or are unsure if it is Christian, compared to only 39 percent of non-evangelicals.

Evangelicals have always considered Mormon religion very different from their own, but sometimes for the wrong reasons. For example, they typically protest that Mormons believe in salvation by good works. Some Mormons do indeed believe this, just as many Catholics and some Protestants believe they will be saved by being good Christians. Yet the Book of Mormon teaches salvation by Christ’s work of grace: “There is no flesh that can dwell in the presence of God save it be through the merits, and mercy, and grace of the Holy Messiah” (2 Nephi 2:8).

Yet evangelicals have legitimate reasons to believe that Mormon beliefs are different from those of historic Christian orthodoxy. For while Mormons believe Jesus is now fully God, they do not believe he was always God. Nor do they believe in the Trinity and the traditional Christian doctrine that God created the world from nothing.

Despite these religious differences, a large majority of Virginia evangelicals—who themselves represent a majority of Virginia voters—say they will vote for Mitt Romney, a Mormon.

But why? Why do an overwhelming majority of Virginia evangelicals (79 percent) say that Romney’s religion “makes no difference” in their voting for him? The answer seems to be that they have seen Obama’s policies and dislike them. Sixty-six percent of evangelicals (vs. only 50 percent of non-evangelicals) disapprove of Obamacare. Evangelicals are just as worried about the economy and the deficit as non-evangelicals. In fact, a majority of evangelicals support the Tea Party (53 percent) while only a quarter (29 percent) of non-evangelicals do. Seventy-nine percent of evangelicals think the country is on the wrong track (vs. 66 percent of non-evangelicals).

Evangelicals, then, will vote against Obama because of the economy and their suspicion that policies such as the recent HHS mandate requiring insurance to pay for abortions will threaten their religious freedom. They will vote for Romney because they think his policies will grow the economy without jeopardizing their deepest convictions—such as their belief in traditional marriage as the bedrock of society.

(Contrary to the current opinion that Romney is losing the women’s vote, 63 percent of Virginia’s evangelicals are women, and they support him over Obama by a broad margin. This means that Romney will win the women’s vote in Virginia, and probably other states with evangelical majorities.)

If evangelicals vote for Romney in greater numbers than for McCain in 2008—and it appears that they might—it won’t be the first time that Christians voted for an American president who was less than orthodox. After all, George Washington was a deist who usually referred to the deity in vague and impersonal terms. Thomas Jefferson believed the doctrines of the Trinity, atonement and original sin were essentially pagan, and rejected the possibility of miracles or resurrection. John Adams also denied the Trinity, along with most orthodox Christian doctrine, while holding to a Stoic-like resignation to fate. Lincoln and his wife attended séances, and William Howard Taft was a Unitarian who rejected the deity of Christ.

Christians who voted for these presidents showed they were looking for a Commander-in-Chief, not a theologian-in-chief. In this approach they echoed Martin Luther, who reputedly said, “I would rather be governed by a wise Turk than by a foolish Christian.”

Gerald R. McDermott is Jordan-Trexler Professor of Religion at Roanoke College, and co-author of Evangelicals and Mormons: Exploring the Boundaries.

Become a fan of First Things on Facebook, subscribe to First Things via RSS, and follow First Things on Twitter.

By NAOMI SCHAEFER RILEY

Charlotte, N.C.

If you’ve been to church lately, you probably know how unusual it is to see a critical mass of young people in attendance. According to studies by the Barna Group, church engagement falls by as much as 43% between the ages of 18 and 29. Which is why the scene on a recent night in uptown Charlotte, N.C., was so remarkable.

Young people were streaming into a beautifully adorned United Methodist Church, and by the time the lights dimmed for the Christian rock band Gungor (and their opening act, The Brilliance), the capacity crowd numbered more than 600. The audience was not, by and large, made up of members of United Methodist.

Rather, the mostly single professionals and students were brought here by Charlotte ONE, a collaboration of 40 or so area churches trying to reach this demographic. Such regular and extensive cooperation of mainline and evangelical Protestant churches from every major denomination is not a typical feature of American religious life. They are more likely to be competing for each other’s members. But desperate times call for desperate measures.

Many of the more than 700 churches in this area (and all over the country, for that matter) have tried to run so-called young-adult ministries—but with little success. James Michael Smith, a co-founder of Charlotte ONE, tells me that a common problem is the return on investment: “Young adults are the least reliable, the most mobile and they don’t give financially either.” In order even to get them in the door, he adds, churches have to offer “the wow factor.”

But the wow factor—expensive bands, charismatic preachers, elaborate social events—doesn’t come cheap. What’s more, many religious leaders worry that offering that kind of experience only encourages young people to think about “the attractional church,” the kind of place you go for entertainment but not for any long-term commitment.

The organizers say they are happy to see the free market at work in other arenas, but they worry that “shopping for God,” as one book title recently had it, is not an appropriate way to view faith.

So a group of evangelical and mainline Protestant leaders here decided to create one young adult ministry that would provide all of the bells and whistles required, without replacing church. Charlotte ONE does not perform baptisms, weddings, funerals or offer communion. It doesn’t meet on Sundays or have a single pastor in charge. Sermons are “bible-based” and generally evangelical in their outlook, but the leaders try to steer clear of controversial issues (religious and political) that might divide their sponsoring churches.

Charlotte ONE’s organizers see it as a kind of “funnel,” taking in a wide swath of people and trying to pour them out in the right direction. The group takes its motivation from Jesus’ words in John 17:23: “Let them be one, so that the world may know that you sent me and loved them even as much as you have loved me.”

Feedback suggests that the effort is meeting its objectives. In one survey, 98% of attendees said the program had “enriched [their] personal relationship with Jesus Christ,” and 42% said that it had helped them “connect . . . to local churches.” Another measure of success is that other religious communities are looking to reproduce the experience. Phoenix ONE launched this spring. One question about these collaborative efforts is whether they serve the larger cause of religion in public life as much as they serve individual churches. Rodney Stark, co-director of the Institute for the Study of Religion at Baylor University, is a skeptic who argues that competition among churches—including “aggressive marketing” of the wow factor kind—has helped to boost church membership. He argues that competition has made America a more vibrant religious marketplace, especially in contrast to Europe.

But competition has downsides as well. The leaders of the Charlotte ONE collaboration call the competition approach “sheep-stealing,” as in poaching from the flock of other churches, and they say that it isn’t very “Christ-like” behavior.

Seeing a company go under because another one made a better widget is not the same as watching a church have to close its doors because the one down the street has hipper music or a better social scene. Even from a nonreligious perspective, there is a cost to competition. Long-term commitment to a church creates the kind of civic capital that every generation—even the millennial-born hipsters—could use.

Ms. Riley writes frequently about religion for the Journal.

A version of this article appeared May 4, 2012, on page A11 in some U.S. editions of The Wall Street Journal, with the headline: Pastors Call a Truce on ‘Sheep-Stealing’.