Snow falls resolutely on a Saturday morning in Washington, but the festively lit basement of a church near the US Capitol is packed. Some 200 female members have invited an equal number of women for tea, cookies, conversation – and 16th-century evangelism.

What newcomers at Capitol Hill Baptist Church (CHBC) hear is hardly "Christianity for Dummies." Nor is it "Extreme Makeover: Born-Again Edition." Instead, a young woman named Kasey Gurley describes her disobedience and suffering in Old Testament terms.

"I worship my own comfort, my own opinion of myself," she confesses. "Like the idolatrous people of Judah, we deserve the full wrath of God." She warns the women that "we'll never be safe in good intentions," but assures them that "Christ died for us so we wouldn't have to." Her closing prayer is both frank and transcendent: "Our comfort in suffering is this: that through Christ you provide eternal life."

It is so quiet you can hear an oatmeal cookie crumble.

IN PICTURES: Calvinism at Capitol Hill Baptist Church

Welcome to the austere – and increasingly embraced – message of Calvinism. Five centuries ago, John Calvin's teachings reconceived Christianity; midwifed Western ideas about capitalism, democracy, and religious liberty; and nursed the Puritan values that later cast the character of America.

Today, his theology is making a surprising comeback, challenging the me-centered prosperity gospel of much of modern evangelicalism with a God-first immersion in Scripture. In an age of materialism and made-to-order religion, Calvinism's unmalleable doctrines and view of God as an all-powerful potentate who decides everything is winning over many Christians – especially the young.

Twenty-something followers in the Presbyterian, Anglican, and independent evangelical churches are rallying around Calvinist, or Reformed, teaching. In the Southern Baptist Convention, America's largest Protestant body, at least 10 percent of its pastors identify as Calvinist, while more than one-third of recent seminary graduates do.

New Calvinism draws legions to the sermons of preachers like John Piper of the Bethlehem Baptist Church in Minneapolis. Here at CHBC, the pews and even rooms in the basement are filled each Sunday, mostly with young professionals. Since senior pastor Mark Dever brought Calvinist preaching here 16 years ago, the church has grown sevenfold. Today it is bursting at the stained-glass windows.

Yet the movement's biggest impact may not be in the pews. It's in publishing circles and on Christian blogs, in divinity schools and at conferences like "Together for the Gospel," where the rock stars of Reformed theology explore such topics as "The Sinner Neither Able Nor Willing: The Doctrine of Absolute Inability."

"There is a very clear resurgence of Calvinism," says Steven Lemke, provost and a professor at the New Orleans Baptist Theological Seminary.

The renewed interest arrives at a crucial inflection point for American religion. After reviewing a landmark opinion survey last year that showed a precipitous decline in the number of people who identify themselves as Christian, Newsweek declared ominously that we may be witnessing "the end of Christian America."

In some ways, Newsweek may have understated the shift. Five hundred years after Martin Luther posted his 95 theses challenging the Roman Catholic Church, some religion watchers see not just a post-Christian America but an unraveling of the Protestant Reformation itself. Their alarm is rooted in surveys that show a watering down of Christian beliefs.

Now come the New Calvinists with their return to inviolable doctrines and talk of damnation – in essence, the Puritans, minus the breeches and powdered wigs. Is this just a moment of nostalgia or the beginning of a deeper revolt against the popular Jesus-is-our-friend approach of modern evangelicalism? Where, in other words, is Christianity going?

• • •

When people today hear the name John Calvin, they think mainly of predestination – the controversial idea that God has foreordained everything that will happen, including who will and won't be saved, no matter what they do in life.

What people often forget is that the 16th-century French theologian transformed Western thought both by what he taught and how he taught it. His 700-page "Institutes of the Christian Religion" became the reference manual for Protestant faith. And his detailed and explanatory style of preaching – he spent five years expounding on the book of Acts, verse by verse – became an example for generations of clergy.

Detractors, and there are many, see Calvin as a harsh theocrat who punished heretics (including one who was famously burned at the stake) while molding the city where he preached, Geneva, into a model of his fatalistic and hopeless ideology.

But supporters view him as a man who recovered God-centric Christianity, set the stage for religious freedom, and encouraged countless believers to read the Bible for themselves.

"Like it or not, he is one of the great minds that shaped our modern world," says Gerald Bray, a professor at Beeson Divinity School in Birmingham, Ala. "Ideas of democracy, open-market capitalism, and equality of opportunity were aired in his Geneva and put into practice as far as they could be at that time."

Calvin's influence on America's founding is unmistakable. The nation's patriotism, work ethic, sense of equality, public morality, and even elements of democracy all sprang in part from the Calvinist taproot of Puritan New England. When Calvinist preacher Jonathan Edwards told worshipers in 1741 that they were loathsome spiders held over the pit of hell by the gracious hand of an offended God, he wasn't speaking a heretical creed but the basic vocabulary of American faith. It wasn't until the 19th century that Calvinist doctrines waned.

By most logic, the stern system of Calvinism shouldn't be popular today. Much of modern Christianity preaches a comforting Home Depot theology: You can do it. We can help. Epitomized by popular titles like Joel Osteen's "Your Best Life Now: 7 Steps to Living at Your Full Potential," this message of self-fulfillment through Christian commitment attracts followers in huge numbers, turning big churches into megachurches.

At the same time, a strict following of the Bible, which Calvinists embrace, hardly resonates the way it once did in American society. The Barna Group, a California-based research firm, recently did a survey to find out how many US adults hold a "biblical worldview" – for instance, believe that the Bible is totally accurate, that a person cannot earn their way into heaven simply by doing good, that God is the all-powerful creator of the universe.

The result: a steeple-thin 9 percent. Among 18-to-23-year-olds, it was 0.5 percent, fewer people than might show up at a Lady Gaga concert. Even among "born again" Christians, it was only 19 percent.

In a separate report, Barna found that more than 6 in 10 born-again Christians say they are customizing their faith, not following any one church's theology. "Americans are increasingly comfortable picking and choosing what they deem to be helpful and accurate theological views and have become comfortable discarding the rest of the teachings in the Bible," the report notes.

The blunt implication: Scripture is no longer the sheet anchor of American spirituality.

This, of course, was the Roman Catholic warning to early reformers five centuries ago: If you break away from the church, orthodoxy will spiral into fancy. By emphasizing sound doctrine and the naked gospel, New Calvinists want to restore what they see as stability to Protestant faith.

Indeed, CHBC has a sister organization called "9Marks," which strives to promote "biblically faithful" churches across denominational lines.

"A lot of people think religion is something you piece together [from] ideas you think are sweet and that you personally find beneficial," says Mr. Dever. "No. It's like a doctor's report.... It's an objective reality. It's just what is."

More broadly, the Calvinist revival reflects an effort to recast the foundation of faith itself. From conservative evangelical churches to liberal new-age groups, the message of much modern teaching is man's need for betterment. Not New Calvinism; its star is God's need for glory. And the gravity of His will is great: It can be denied, but not defied.

"God either knows everything, or He knows nothing at all," says CHBC member Jeannie Hagopian, a young mother from South Carolina.

• • •

As morning light filters into a fourth-floor room on a Sunday, students huddle on tiered seats, listening to a lecture on substitutionary atonement. The teacher poses a tough question, but a hand shoots into the air, eager to answer with a recitation of the week's memory verse from I Peter 3:18: "For Christ died for sins once for all, the righteous for the unrighteous, to bring you to God."

Scholars and seminarians call this systematic theology. Kindergartners at CHBC just call it Sunday school.

Their parents are downstairs, absorbing seminars, prayers, and a Scripture-saturated sermon that add up to five hours of worship over the day. Just before noon, the adults jot notes as they listen to an hour-long sermon on II Samuel 5-9. These chapters cover King David's glorious reign over Israel, but Dever doesn't skip the tough verses, such as when God strikes Uzzah dead for trying to steady the ark of the covenant.

"Friends, have we sinned like Uzzah?" he asks.

Such statements are meant to prick the hearts of his listeners. Yet he often follows up the hard questions with reassuring comments like: "You and I should not draw a breath today, without living for the praise of God's glory."

This pattern – convict worshipers of their sin, then show them spiritual elation – has a gripping effect on the assembly. After the service, churchgoers linger for an hour, hugging and sharing heartfelt conversation. "I've come to believe and understand that God is not fundamentally about me; He's much bigger than that," says Dan Wenger, a government employee. "The teaching at this church has helped me to see that in context of the whole story of the Bible, not just the parts that make me feel good."

Dever acknowledges that people might well ask, "Why would God make anybody who is going to go to hell?" His answer captures the essence of New Calvinism. "I don't know," he says. "I didn't do this. I'm just trying to tell you what I think is true, not what I like."

Membership at CHBC isn't for the faint of holy. Classes on theology and Christian history are required before joining. At the "Lord's Supper" once a month, members stand and recite an oath that ties them to one another. In addition to Sunday worship and Wednesday night Bible study, they spend hours each week in small-group study or one-on-one "discipling." They say those sessions – a time for confessions, encouragement, and prayer – are the most challenging and rewarding feature of church life.

"Christian fellowship is so much more than hanging out with friends," says Claudia Anderson, a magazine editor. "It involves spiritual intimacy, support, learning, counseling, and stunning acts of kindness."

Christopher Brown, a lawyer, concurs. "I came for the theology but stayed for the community," he says. "As Americans, we're so individualistic. But the New Testament rebukes this 'rugged individualism.' We're not saved to be lone rangers."

The BlackBerry-wielding Millennials who worship here say they crave teaching that challenges them – "preaching for PhDs," as one puts it. Ask them what books they're reading, and they won't mention "The Girl with the Dragon Tattoo." They'll reel through names of 17th-century Puritan preachers like a pack of baseball cards.

"The resurgence of Calvinism indicates that America hasn't changed so much as some might suppose," says Collin Hansen, author of "Young, Restless, Reformed: A Journalist's Journey with the New Calvinists." "American Christianity has splintered in myriad directions since the Puritans settled New England. But the God they worshiped – attested in the Bible, sovereign in all things, and merciful toward sinners through the self-sacrifice of Jesus Christ – still captivates believers today."

• • •

What captivates outsiders, however, is that New Calvinists are restoring the doctrine of predestination – God choosing from the outset whom He will and won't save – to a land that long ago shifted toward a "No Child Left Behind" view of salvation. Taken to its logical end, predestination means God has always regulated everything, even evil.

This belief bothers many Christians. "The shooting at Fort Hood: Did God foreordain that? 9/11? The Holocaust?" asks Professor Lemke, who's also a Baptist pastor and critic of some, though not all, points of Calvinism.

In 2008, Southern Baptist organizers put on a John 3:16 conference to counterbalance tenets of Calvinism, including predestination. [Editor's note: The original text misstated who put on the John 3:16 conference.]

What critics see as a grim and fatalistic doctrine, however, Calvin saw as good news: that God's purposes can be fulfilled despite man's sinful ways.

"To him, predestination was a liberating belief because it says that God can choose anyone, however humble, and use him to overturn the great men of this world," says Professor Bray. "It makes real change possible and puts ordinary people like you and me in charge of seeing it happen. What could be better news than that?"

Many followers agree, adding that Calvinism is not fatalism: You are responsible for you behavior.

"Calvinism is 'big picture' Christianity," says Allen Guelzo, the author of "Edwards on the Will: A Century of American Theological Debate." "It is less interested in asking why God lets bad things happen to good people, and asks instead whether there have ever been any genuinely 'good' people."

For all its controversy, predestination is something New Calvinists accept as part of their take-it-all-or-leave-it approach to the Bible.

"Today we have more Bibles and more study guides to Scripture than ever before, but people know the text itself less and less," says Bray. "This is disastrous. Calvin's deep and expository approach to it is therefore more necessary than ever."

At CHBC, several members say they became authentically Christian only after a friend studied the gospel with them verse by verse. "As I studied the Bible, I saw that God has every reason to send me to hell," says Connie Brown, a kindergarten teacher. "God broke me down – and renewed my heart."

New Calvinists talk about their sin a lot. Despite that – or rather because of it – they exude not guilt but great joy. Their explanation: If we play down our sinfulness, we'll play down our gratitude for the magnitude of God's love and forgiveness.

Many members were drawn to CHBC precisely because they had yearned to be "convicted of their sin" again and grown frustrated with "watered-down preaching." School vice principal Jessica Sandle says she came after the pastor at her former church read a book on growth and became consumed with filling pews. "So he stopped talking about sin, and why we need God," she says.

Another congregant, who declined to be named because he is running for office, was searching for something more substantial as well. "I went to other churches and I came away feeling good, but I came away hungry, too," he says. "They [the sermons] were mercifully shorter, but they'd leave the gospel out, and I wouldn't be convicted of my sin.... Here, your deficiencies are laid bare."

Ultimately, Calvinism's contrast with chummier, Jesus-is-my-friend forms of evangelicalism may highlight a more fundamental change in the world of faith. Bestselling religion writer Phyllis Tickle sees the interest in Calvinism as the first phase of a backlash against the dominant religious trend of today: the rise of "Emergence Christianity."

Emergence Christianity, which she identifies as a once-every-500-years religious shift, is less a doctrine or a movement than a postmodern attitude toward religion itself. Loosely organized, it values experimentation over traditional rules and Christian practice.

"When things go through this upheaval," Ms. Tickle says, "there's always those who absolutely need the assurance of rules and a foundation."

Or, as Ms. Hagopian puts it with uncompromising Calvinistic clarity: "The dominant philosophy of American Christianity is so far removed from biblical truth. Life is not hunky-dory."

IN PICTURES: Calvinism at Capitol Hill Baptist Church