LMOST anywhere you look around the world, with the glaring exception of Western Europe, religion is now a rising force. Former Communist countries are humming with mosque builders, Christian missionaries and freelance spiritual entrepreneurs of every possible persuasion. In China, underground "house churches" are proliferating so quickly that neither the authorities nor Christian leaders can keep reliable count. In much of South and Central America, exuberant Pentecostal churches, where worshipers catch the Holy Spirit and speak in tongues, continue to spread, challenging the Roman Catholic tradition. And in the United States, religious conservatives, triumphant over their role in the re-election of President Bush, are increasingly asserting their power in politics, the media and culture.

The tsunami in Asia could spur religious revival as well, as victims and onlookers turn to mosques, temples and churches both to help them fathom the catastrophe and to provide humanitarian assistance.

What does all this rising religiosity add up to? It is easy to assume that a more religious world means a more fractious world, where violent conflict is fueled by violent fundamentalist movements. But some religion experts say that while it is clear that religiosity is on the rise, it is not at all clear that fundamentalism is. Indeed, there may be a rising backlash against violent fundamentalism of any faith.

The world's fastest growing religion is not any type of fundamentalism, but the Pentecostal wing of Christianity. While Christian fundamentalists are focused on doctrine and the inerrancy of Scripture, , what is most important for Pentecostals is what they call "spirit-filled" worship, including speaking in tongues and miracle healing. Brazil, where American missionaries planted Pentecostalism in the early 20th century, now has a congregation with its owns TV station, soccer team and political party.

Most scholars of Christianity believe that the world's largest church is a Pentecostal one - the Yoido Full Gospel Church in Seoul, South Korea, which was founded in 1958 by a converted Buddhist who held a prayer meeting in a tent he set up in a slum. More than 250,000 people show up for worship on a typical Sunday. "If I were to buy stock in global Christianity, I would buy it in Pentecostalism," said Martin E. Marty, professor emeritus of the history of Christianity at the University of Chicago Divinity School and a coauthor of a study of fundamentalist movements. "I would not buy it in fundamentalism."

After the American presidential election in November, some liberal commentators warned that the nation was on the verge of a takeover by Christian "fundamentalists." But in the United States today, most of the Protestants who make up what some call the Christian right are not fundamentalists, who are more prone to create separatist enclaves, but evangelicals, who engage the culture and share their faith. Professor Marty defines fundamentalism as essentially a backlash against secularism and modernity.

For example, at the fundamentalist Bob Jones University, in Greenville, S.C., students are not allowed to listen to contemporary music of any kind, even Christian rock or rap. But at Wheaton College in Illinois, a leading evangelical school, contemporary Christian music is regular fare for many students.

Christian fundamentalism emerged in the United States in the 1920's, but was already in decline by the 1960's. By then, it had been superceded by evangelicalism, with its Billy Graham-style revival meetings, radio stations and seminaries. The word "fundamentalist" itself has fallen out of favor among conservative Christians in the United States, not least because it has come to be associated with extremism and violence overseas.

Fundamentalism in non-Christian faiths became a phenomenon in the rest of the world in the 1970's with "the failure and the bankruptcy of secular, nationalistic liberal creeds around the world," said Philip Jenkins, a professor of history and religious studies at Pennsylvania State University. Among the "creeds cracking up" were nationalism, Marxism, socialism, pan-Arabism and pan-Africanism. "From the 1970's on, you get the growth of not just more conservative religion, but religion with a political bent," said Professor Jenkins, the author of "The Next Christendom: The Coming of Global Christianity."

Now, the future of fundamentalism is murky, with several contradictory trends at work simultaneously. There is little doubt that one fundamentalism can feed another, spurring recruitment and escalating into a sort of religious arms race. In Nigeria's central Plateau State, Muslim and Christian gangs have razed one another's villages in the last few years, leaving tens of thousands of dead and displaced. In rioting in India in 2002, more than 1,000 people, most of them Muslims, were killed by Hindus in Gujarat state - retaliation for a Muslim attack a day earlier on a train full of Hindus, which killed 59.

Husain Haqqani, a Pakistani political commentator and visiting scholar at the Carnegie Endowment for International Peace in Washington, said that insurgents in Falluja, Iraq, recruited fighters with the false rumor that Christian crusaders with the Rev. Franklin Graham's aid organization, Samaritan's Purse, were on the way over to convert Muslims. (Mr. Graham is known throughout the Muslim world for his statement that Islam is a "very evil and wicked religion.") Fundamentalism does not necessarily lead to intolerance, said Professor Jenkins of Pennsylvania State. "People with very convinced, traditional views can get along together for a very long time," he said. "But sometimes we get into cycles where they can't, and we seem to be in one of those cycles right now."

Analysts are also seeing signs of a backlash as religious believers grow disenchanted with movements that have produced little but bloodshed, economic stagnation and social repression. In last year's elections in India, voters repudiated the ruling Bharatiya Janata Party, a Hindu nationalist group whose cadres had helped stir up violence in some Indian states against Muslims and others.

And in Indonesia, the world's largest Muslim country, mainstream Islamic groups in September helped elect as president a secular general who had been relatively outspoken about the threat posed by the radical group Jemaah Islamiyah, which is responsible for several acts of terrorism, including the bombing in Bali in 2002.

Fundamentalist movements also stumble because they plan for the overthrow, but not for the governing. Half the Muslim world is illiterate, Mr. Haqqani said, but the Taliban didn't make a dent in improving literacy when it ruled in Afghanistan. If Iran had a free and fair plebiscite today, Professor Marty said, "the ayatollahs would be dumped."

For reasons like this, said R. Scott Appleby, a history professor at the University of Notre Dame and director of the Joan B. Kroc Institute for International Peace Studies, "it would be misleading to say fundamentalism is on the rise now." He added: "I would say we're just more aware of it because these people are better organized, more mobile and more vocal than ever before."

In 2003, Professor Appleby and two other scholars, Gabriel A. Almond and Emmanuel Sivan, published "Strong Religion," a book based on research done with Professor Marty for the Fundamentalism Project. The book's subtitle was the "The Rise of Fundamentalisms Around the World." Now, Mr. Appleby said, "There is some evidence, some literature that says fundamentalism is on the decline, that it has peaked or is peaking precisely because it has a tendency toward violence and intolerance, and those ultimately don't work. They lead to bloodshed, loss of life, and no recognizable economic upturn, and there is an exhaustion with it."

That is not to say that he does not foresee more bitter, sometimes violent religious clashes. By their very nature, fundamentalists endure because they are motivated by transcendant ideas like salvation or, in some places, martyrdom. Mr. Appleby said he did not expect to see growth, but a persistence of "deadly pockets of would-be revolutionaries who are empowered to a greater degree than ever by a little technological savvy and organizational ability."

The American government is poorly prepared to make the necessary distinctions between what is merely religious fervor and what is potentially dangerous fundamentalism, said Thomas F. Farr, who left his post as director of the office of international religious freedom in the State Department about a year ago. "Most of my foreign service friends would rather have root canal than talk to a Muslim imam about religion," said Mr. Farr, who now works with the Institute for Global Engagement, a Washington-based group working on international religious freedom.

What they need to ask, he said, is: "Do these religions have within them exclusivist tendencies in an absolutist sense, or can they be open to other human beings outside their circle? These are inevitably theological questions."