Church attendance in Ireland, though still among the highest in Western Europe, has fallen from about 85 percent to 60 percent from 1975 to 2004, according to the Dublin Archdiocese.

While it is still illegal for a woman to have an abortion in this mostly Roman Catholic country, Health Minister Mary Harney made front-page news in July when she said birth control pills should be available for girls as young as 11 in some circumstances. And for the first time, according to church records, not one priest will be ordained this year in Dublin.

Mary Haugh, who has gone to Mass here seven days a week for almost all of her 79 years, is saddened. ''It's a Godless society,'' she says.

Ireland is not an exception. Every major religion except Islam is declining in Western Europe, according to the Center for the Study on Global Christianity at the Gordon-Conwell Theological Seminary in South Hamilton, Mass. The drop is most evident in France, Sweden and the Netherlands, where church attendance is less than 10 percent in some areas.

Last month, Pope Benedict XVI lamented the weakening of churches in Europe, Australia and the United States. ''There's no longer evidence for a need of God, even less of Christ,'' he told a meeting of Italian priests. ''The so-called traditional churches look like they are dying.''

The forces driving the decline include Europe's turbulent history, an increasing separation between the church and government - and perhaps most of all, the continent's unprecedented affluence.

''For most of history, people have been on the borderline of survival,'' says Ronald Inglehart, director of the World Values Survey, a Swedish-based group that tracks church attendance. ''That's changed dramatically. Survival is certain for almost everyone [in the West]. So one of the reasons people are drawn to religion has eroded.''

One result is fewer children: Among the most striking consequences of the decline of religion has been fewer children. The birth rate throughout much of Western Europe has fallen so drastically that the population in many countries is shrinking, indicating that women throughout Europe now routinely use artificial birth control, in defiance of the Roman Catholic Church's teachings.

''The biggest single consequence of the declining role of the church is the huge decline of fertility rates,'' Inglehart says. With fewer people entering the workforce, countries like Italy, Germany and France won't be able to maintain the generous welfare programs that have given most workers a lifetime of economic security.

''The declining [church] attendance is really dramatic, but what is even more important is that the churches are losing the ability to dictate to people how to live their lives,'' Inglehart says.

In 1900, almost everyone in Europe was Christian. Now, three out of four people identify themselves as adherents to Christianity. At the same time, the percentage of Europeans who say they are nonreligious has soared from less than 1 percent of the population to 15 percent. Another 3 percent say they don't believe in God at all, according to the Center for the Study of Global Christianity.

In 12 major European countries, 38 percent of people say they never or practically never attend church, according to the World Values Survey in 2000. France's 60 percent nonattendance rate is the highest in that group. In the U.S., only 16 percent say they rarely go to church.

Not just the Catholic Church: Andrew Greeley, a priest, professor at the University of Chicago and prolific author on Christianity, argues that despite the decline in church attendance, Christianity is not on the wane everywhere in Europe. ''Religion declined abruptly in England and the Netherlands. It is stagnant in West Germany, and it is flourishing in Poland, Slovakia and Slovenia,'' he says. ''I get upset about the sweeping generalization about the decline in religion. Religion is always declining and always reviving.''

It is not just the Catholic Church that has seen its numbers fall; some Protestant churches have been affected. Among the most striking examples is the Swedish Lutheran Church. For generations, ''You didn't become a member when you were baptized. You became a member when you were born,'' says Carl Johan Liden, a priest in Stockholm.

In 2000, the church was separated from the state as part of the country's secular trend. People now can send a letter to their local parish telling the vicar they no longer wish to be a member and opt not to pay taxes to the church, which range from about 2 percent to 3 percent of their income.

The battle is more apparent in Western Europe, where a half-century of peace has meant economic and political stability. World Bank data show the per capita gross domestic product in Western Europe has tripled since 1980.

Eastern Europe is different: It's a different story in Eastern Europe, where the economies are weaker - and citizens less secure. That partly explains why religion remains strong in countries such as Russia, Poland and Ukraine. ''For the masses, religion provides a sense of certainty in an uncertain world,'' he says. And since the collapse of communism and its anti-religious ideology, people in Eastern Europe are taking advantage of their new freedom to worship.

As Western Europeans have moved away from traditional worship, more people say they are ''spiritual'' rather than religious. Steve Hollinghurst, an Anglican priest in Britain says, ''It's very much what's appealing to people now - spirituality that works with my lifestyle. It's almost a designer spirituality, as opposed to off-the-shelf. Faith and spirituality are now viewed as consumer products. And that's had an impact on the way people view institutional churches.''

''Materialism has taken over. It has replaced God,'' says Haugh, the Dublin churchgoer.

But Kenny, the Dublin student, says he's merely typical of his generation. ''I'm very spiritual,'' he says. ''I speak to an energy force I call God, and I get answers,'' he says. ''If you can get a spiritual connection without going to church, why go to church?''