THE crowd in the war-memorial coliseum was a slung hash of the premillennial middle class -- gaunt-looking slackers in Doc Martens and consignment-store flannel shirts, and black, clean-cut kids in white Ts and lettermen's jackets; suburban moms with frizzy perms, and little kids eating pink cotton candy. Nobody smoked even in the parking lot outside, which was dotted with utility vans from places like First Eel River Baptist Church. They booed before the show when it was announced that there would be no mosh pit or body surfing. They whooped ''Alleluia!'' and ''Praise Jesus!'' when the lead singer ended the night with a sermon that sounded like Ecclesiastes meets Kurt Cobain, about the vanity of all that is not Jesus.

It was a concert by DC Talk, a band that plays everything from hip-hop to grunge to crooning urban soul to unplugged ballads -- three guys who met at Jerry Falwell's Liberty University and have gone on to make a name for themselves as the hottest act in what's known as Christian contemporary music, which in turn is on the cutting edge of a burgeoning pop Christian culture in America.

I saw DC (for Decent Christian) Talk in Fort Wayne, Indiana, one of those anonymous all-American cities that's as far away from the Bible Belt, in spirit and in truth, as you can get. It's in cities like this -- Ottumwa, Iowa; Belton, Texas; Kearney, Nebraska --that a low-intensity cultural revolution is taking place.

And while this mission to post-Christian America has thus far stayed below the radar of the nation's cultural and political establishments, it is hard to fully understand the late-twentieth-century U.S.A. without taking note of the fact that more and more Americans are putting their treasure where their heart is. The Christian Booksellers Association says Americans are spending about $3 billion a year on things Christian.

To be sure, this is still a small subculture driven by a narrow brand of Christianity --evangelical and fundamentalist. By contrast, Catholics and mainline Protestants have little appetite and no aptitude for this wholesale taking of the Gospel straight to the people in the marketplace.

''There is a movement, a search for something sacred and spiritual, and we are trying to meet that demand,'' says Rachel Deems. Mrs. Deems is president of Disciples, the world's first Christian ''superstore,'' which opened outside Birmingham, Alabama, late last year. Disciples and other stores like it are symbols of the confident suburbanization of the salvation message, appealing mainly to married white women in their thirties and forties who are buying goods to bolster the faith of their young families. Disciples is a 25,000-square-foot horn of plenty where God and Mammon mingle on easy and familiar terms; it boasts 100,000 books and a 300-yard espresso bar where Christian singles come to meet and exchange business cards.

Christian retailing used to mean the Bible, and the Bible remains the single biggest-selling item in the nation's 2,500-plus Christian bookstores. But the immutable Word of God has been re-formatted for the neurotic Nineties -- there are now specialty Bibles aimed at the recovering boozer and drug addict, co-dependents of various stripes, pregnant women, restless teens, even computer freaks.

And the Bible isn't the only book evangelicals are reading. Although they long ago shucked off the need for a Pope to tell them what Scripture means, evangelicals are buying tens of thousands of books by people like Dave Hunt and Max Lucado to help them live sola Scriptura and engage in ''spiritual warfare.''

But the market in Gospel ''truth'' is wholly unregulated, and there's one big caveat emptor: a lot of what's on the sagging shelves of ''end times'' Bible-prophecy studies is just an aggressive new gloss on old prejudices and decoder-ring theories of sacred Scripture -- the Pope is the Antichrist and the Roman Church is Revelation's ''whore of Babylon''; the Jews will get one final chance to convert as Gog and Magog clash in the late great planet earth's last world war.

Christians are also spending some $60 million a year to literally wear their faith on their chests. They buy ''God's Gym'' workout tops and ''Gone to See Dad'' T-shirts. For kids, there are a half-dozen God-fearing alternatives to Power Rangers and Ninja Turtles, including ''Chariot Family,'' a collection of Philistine and Israelite action figures. Another hot seller with kids is ''Veggie Tales'' videos -- funny and sophisticated computer-animated adaptations of Bible stories, hosted by a tomato named Bob and a cucumber named Larry.

For grownups, there are Christian nightclubs like Club J in San Jose, which specializes in Christian rave and techno dance music. Club J serves no adult beverages, and the bouncers dress in referees' uniforms and blow whistles when the gyrating gets a little too unorthodox.

With such a proliferation of products and services, it is easy to forget that the traditional mainstays of Christian pop culture --radio and TV -- are now available to every household in the country. The Christian media have moved beyond polyester-clad faith healers and mascara-running testimonials. There are hundreds of Christian sites on the Internet, and Z Music, a Christian rock channel, reaches 17 million homes, with videos indistinguishable from those on MTV except that the girls keep their clothes on and the messages are ethereal, not suicidal.

Snubbed by the scribes and high priests in the temples of American culture, the entrepreneurs of evangelicalism have not been treated so sanctimoniously by the money changers. Christian artists like DC Talk, Jars of Clay, Michael W. Smith, and Carman are regulars on Billboard's Top 200, and Christian books and records are sending down profits from Heaven for chains like Waldenbooks, Barnes & Noble, Wal-Mart, and Tower Records. Every major Christian record label is now owned by a secular media conglomerate such as Warner Brothers, Sony, or EMI. Christian acts like Fleming and John are turning up on late-night shows like Conan O'Brien's.

WHAT is going on here? If you ask Paul Hart, a goateed 24-year-old hipster in a brakeman's cap who edits a Christian magazine called One Way, he'll quote St. Paul and say he too is trying to be ''all things to all men, that I might by all means save some'' (see I Corinthians 9:22).

''This is a sights-and-sounds generation,'' Hart told me at a Christian rave party recently. ''If Jesus was around today, he would use music to reach kids.''

This is an attitude that has long characterized American Protestantism, says R. Laurence Moore, a Cornell historian and authority on the history of religious merchandising. He says the fact that America has no state-sponsored religion -- and therefore few secular benefits to be gained from church membership and no coercion to believe -- has always forced churches to be, in effect, salesmen for their Lord.

As Moore notes, the most popular form of literature in nineteenth-century America was the Christian novel. Filled with lurid depictions of seduction, forced prostitution, rape, and baby-killing, this fiction appealed to the prurient lurking in the breast of every Puritan and at the same time taught the moral that the wages of sin is death, or at least serious unhappiness. As late as the 1950s and early 1960s, Christian pop culture was Main Street U.S.A. -- preachers like Fulton Sheen and Norman Vincent Peale and shows like Lamp unto My Feet were fixtures on the nation's networks.

Today, the cultural landscape is dramatically altered -- Christians have been banished from network prime time, and in general the commercial culture has taken a frosty turn against organized religion. Evangelical Protestants have responded by going underground, creating in the cultural catacombs their own alternative nation by cloning virtually every conceivable element in the dominant culture.

But you won't catch Christian pop doing art for art's sake. ''That is the motto of the world. As a Christian, we do art for the sake of Christ,'' according to Carman, one of the biggest-selling entertainers in the world today, who can command concert audiences of up to seventy thousand.

A similar missionary approach is taken by Frank Peretti, who has sold more than seven million of his novels, which are combinations of Cujo and ''Sinners in the Hands of an Angry God,'' and by Janette Oke, who has sold more than 13 million books and whose current effort, A Gown of Spanish Lace, last year sold more than the latest by John Irving, James Michener, and Jackie Collins.

Despite their success, Miss Oke and Mr. Peretti will never appear on the Publishers Weekly or New York Times bestseller lists. Because of the way the bookstores surveyed for these lists are chosen, Christian books are segregated in a literary ghetto, although most of them are at least equal in literary merit to Danielle Steele and The Bridges of Madison County.