ROME (By Laurie Goodstein, NYTimes) April 14, 2005 - No matter who is chosen as the next pope, John Paul II has left behind a generation of committed young Roman Catholics who are already shaping the church in a more conservative mold than did their parents. Church leaders call them Generation John Paul II.

At Catholic universities, these are the students studying the "theology of the body" - John Paul's theological justification for a conservative sexual ethic that includes opposition to contraception, abortion, premarital sex and some forms of assisted reproduction.

In seminaries, they are the young priests who wear the long black cassocks cast off by an earlier generation of Vatican II priests.

In their parishes, these are the youth group members who are reviving traditional spiritual practices like regular recitations of the rosary or "Eucharistic adorations" - praying for long stretches in front of the consecrated host.

"One of the great shocks to me was how conservative the people younger than me are, and these are Catholics from all over the world, not just the United States," said James Keating, 40, an American theologian who is spending his sabbatical in Rome running the Lay Center at Foyer Unitas Institute, a guesthouse for Catholic students.

"Their Catholicism is quite focused on John Paul II, especially his teachings on contraception and the family," said Mr. Keating, who teaches at Providence College in Rhode Island. "It's fairly significant. They are a force in the church."

John Paul II made evangelization of youth a priority of his pontificate. He appeared at World Youth Day events in cities around the world every two years, often choosing sites in countries he considered to be bastions of secularism: Denver, Paris, Rome, Toronto. These were open-air events held in stadiums or fields, and the pope used them to inspire his young flock to lead lives consistent with Catholic teaching.

Another World Youth Day is planned for Cologne, Germany, in August 2005.

One of the first tests for the next pope will be whether he can relate to these young people, a concern that is now preoccupying the cardinals who will begin meeting on Monday to select the next pope, according to interviews with church leaders.

Many of the young people who went to the World Youth Day events or flocked to Rome last week on a "pilgrimages" to John Paul's funeral readily admitted that while they adored John Paul, they did not live by what he preached. They were drawn by the pilgrimage experience, or by the pope's aura, not necessarily the message.

Indeed, not all younger Catholics have embraced John Paul's strict teaching on sexual morality; there are many who want the church to be more flexible about its ban on contraception, its hard line on divorce and its exclusion of women and married men from the priesthood.

But John Paul left behind enough of a committed core of young Catholics who are now becoming the church's Sunday school teachers, youth group leaders, theologians and priests.

Jennifer Miller, 24, from North Carolina, who is studying philosophy and the "theology of the body" at the Angelicum in Rome, said she has been delighted to discover that many younger Catholics, especially the priests, are theological and cultural conservatives like herself.

"I was recently living in Louisiana and saw it especially in the priests," she said. "They're very conservative, especially concerning the theology of the body. They're not afraid to preach it. And they have the parishes that grow."

Stephan Kampowski is a 32-year-old doctoral student from Germany at the John Paul II Institute for Studies on Marriage and the Family at the Pontifical Lateran University in Rome. He said that what the church teaches about sexual morality, about marriage, "is not imposing on human freedom, it is not restricting us, but it is calling us to be all that we can be."

"In the past 12 years I have lived with young Catholics of my age who shared my convictions," he said. "They are there, from all kinds of different countries, so I don't feel I'm odd."

Part of the reason for the worldwide swing toward conservatism among young Catholics is that the pope encouraged the growth of conservative lay-led movements. There are thousands of such movements but among the largest are Opus Dei, the Neocatechumenal Way and Communion and Liberation, some of which also count clergy as members. They often recruit from universities, and live in communities that are devoted to service work and an active prayer life.

The Shalom Community is one example of a movement that is shaping the church in a more theologically conservative direction by reaching out to youth. It was founded in Brazil in 1982 to counter the influence of "liberation theology," a stream of Catholicism then influential in Latin America that championed the rights of workers and the poor. John Paul regarded the liberation theologians as Marxists, and their power diminished during his papacy.

"The pope gave his encouragement to us because liberation theology was not very orthodox," said Maria Emmir, one of the founders of the Shalom Community, which she said had about 50,000 members worldwide. "The lay movements are more linked to Rome than to liberation theology."

Data from the World Values Survey, gathered by researchers in 58 countries, tends to bear out impressions of a conservative trend. It shows that the "millennial generation" of young Catholics - those born in 1982 or later - has returned to the traditional religious attitudes and behavior of generations born before World War II, said Mark M. Gray, a research associate at the Center for Applied Research in the Apostolate at Georgetown University. The values survey, coordinated by the University of Michigan, has been conducted periodically since 1981 by researchers who pool their data and make it available to scholars.

Catholics in the "millennial generation" are more likely to attend Mass weekly, pray every day, feel that religion is important and have a lot of confidence in the church than Catholics in either the Vatican II generation (born 1943 to 1960) or those in the Post-Vatican II generation (1961 to 1981), he said.

Mr. Gray, however, cautioned that the trend is preliminary because only the "leading edge" of the millennial generation were old enough to be making decisions independent of their parents. In addition, the survey's sample size for young people was significantly smaller than for the older age groups.

Sister Mary Bendyna, executive director of the Georgetown center, said young Catholics seemed to be "more receptive to the church, they participate more than their Generation X brothers and sisters, and are a little less cynical about institutions in general, the church included."

They are theologically conservative, but not conservative across the board when it comes to political issues, she said.

"They are more involved in traditional conservative religious practices, but they're very receptive to social justice messages about serving the poor," she said.

Msgr. John J. Strynkowski, a former official at the United States Conference of Catholic Bishops and now rector of St. James Cathedral in Brooklyn, says he sees the phenomenon as "a return to traditionalism."

In the 1970's, in the wake of the Vatican II Council, he said, priests let many traditions fall by the wayside. Now, he said, the younger generation is reviving devotional practices more familiar to their grandparents than their parents.

This trend might not be limited to Catholic youth. Leaders of other faiths, including Jews and Muslims in the United States, say that in recent years they too have noticed a renewed interest in traditional religious practices among young people who are engaged in their religion, raising the possibility that the John Paul II generation of Catholics may simply be mirroring a larger generational trend.