DUBLIN -- The cavernous, cinderblock construction of the Church of the Most Precious Blood, built in 1954 in a solidly working-class neighborhood here, reflects an era when Ireland's priests could marshal one of the world's most devout Roman Catholic flocks for Mass each Sunday and on other days of obligation.
A half-century later, the massive church was nearly empty during Mass on a recent Sunday -- its cold, cement walls echoing with the thin coughs of elderly women, who seem to make up the majority of parishioners in many Irish parishes.
Here and across Europe, Catholicism is withering after decades of steady erosion from the forces of secularism, consumer culture, and the fallout from priest sex abuse scandals.
In some of Catholic Europe's largest dioceses in Germany, France, Italy, and Ireland, the percentage of Catholics who attend Mass regularly has slipped to as low as 20 percent, and in a few cities, like Paris, has reached as low as the single digits, according to figures compiled by the church.
The new pope, Benedict XVI, who hails from Germany, has said that the erosion of the church in Europe is one of the greatest challenges facing his papacy. He has called on Catholics to resist ''a dictatorship of relativism" in the modern, secular West that he believes has damaged the Christian foundation of Europe.
In his just-published book, ''Values in Times of Upheaval," the pope, who was then still known as Cardinal Joseph Ratzinger, ruminated on the besieged soul of Christian Europe. ''In order to survive, Europe needs a critical acceptance of its Christian culture. Europe seems, in the very moment of its greatest success, to have become empty from the inside. Crippled, as it were," he writes.
How to heal the church looms over the next papacy, and those who know and work with Benedict say he is intent not so much on reaching out to the wayward many, but on turning inward and strengthening the core of the faithful few.
The commitment to this approach is revealed in Benedict's choice of his papal name. St. Benedict was a sixth-century monk who, when faced with the decay of the Holy Roman Empire and the onslaught of the barbarians, retreated to establish hilltop monasteries. The monasteries spread and became the foundations from which European Christendom was built.
The Rev. Augustine DiNoia, who worked closely with Ratzinger as the undersecretary of the Congregation for the Doctrine of the Faith, said, ''This idea of turning inwards and reflecting is how we will see the pope confront the weariness of the church in Europe."
One of the most important efforts to stem the tide shifting away from the church in Europe, DiNoia and other church officials say, will be reaching out to youth. But Benedict is likely to take on this task in a different way, DiNoia said, when he makes what is expected to be his first foreign journey as pope to the church's World Youth Day, a hallmark of the previous papacy, which is scheduled for August in Cologne, Germany.
''Pope John Paul II might be seen as having called the youth, especially in Europe, together in big rallies, demonstrations of faith. But this pope is more likely to guide them to find a more quiet, reflective place. This pope will perhaps call for a more interior experience," DiNoia said in a telephone interview.
The percentage of Catholics who attend Mass in Europe has plummeted in the last quarter-century.
Church attendance statistics tend to be high, say sociologists who have found a tendency among those polled to say they are going to church even when they do not. Even with that caveat, the numbers show a dramatic decline.
In Italy, where 97 percent of the population considers itself Catholic, church attendance has fallen to 30 percent, according to figures compiled by Famiglia Cristiana, a popular Catholic weekly magazine. In large cities such as Milan, the figure is no more than 15 percent, church officials say.
In France, where 76 percent of the population considers itself Catholic, only 12 percent say they go to church on Sunday, according to Georgetown University's Center for the Study of Global Christianity, and Vatican officials say the percentages attending Mass drop as low as 5 percent in cities, such as Paris.
In Ireland, where 90 percent of the population is nominally Catholic, less than 50 percent attend Mass even once a month, according to church officials' estimates. That figure is more dramatic given that 91 percent of the country attended Mass regularly just 30 years ago, according to a recent church study.
The decrease in the number of men entering the priesthood across Europe, with the notable exception of Poland, is equally dismaying for Catholics. In Ireland, for example, the Archdiocese of Dublin ordained only one priest last year. This year, for the first time in what historians say is hundreds of years, the diocese says it does not expect to ordain a single priest.
Each traditionally Catholic country in Europe has its own historical circumstances that have shaped the declining influence of the church.
In Spain, the church is still in the process of emerging from the shadow of its alliance with the dictator Francisco Franco, who came to power in the late 1930s during the Spanish Civil War and reigned until his death in 1975, and has steadily seen its hold on government slip. Laws against divorce and abortion have eased, and the year-old governing coalition, headed by the Socialist Party, has passed preliminary legislation to make gay marriage legal.
In Poland, where the church remained vibrant under the papacy of John Paul II, priests say the church feels suddenly adrift in the absence of its native son.
In France, the fiercely secular culture has badly eroded the church and penetrated all spheres of life to the point where most of the country's grand cathedrals are visited more by tourists than the faithful. The most recent manifestation of what some analysts call France's secular fundamentalism was last year's legislation that banned Islamic head scarves and all other symbols of conspicuous religiosity from French classrooms.
The tragic history of World War II looms over the decline of the church in Germany. Across college campuses in the 1960s, militantly secular and often atheistic student movements blamed the German establishment -- political and religious -- for Nazism and sought to tear it down to build a new, modern Germany. The decades of secularization following the upheaval battered the church.
Even at the celebratory Mass for the new pope in his Bavarian hometown of Traunstein, there were no more than 75 parishioners in the church that held up to 1,000.
When asked how he felt about Pope Benedict, Hans Kosterke, 58, a civil servant in the town hall who attended the Mass, replied: ''I am happy he is one of us, a Bavarian. But I don't think his papacy will do anything to get young people back in church."
The Rev. Joseph Fessio, a professor at Ave Maria University in Naples, Fla., who in the 1970s studied in Germany under Ratzinger, said, ''The reason they aren't excited is because his whole country has lost its faith. Get the stats on births, the number of abortions, the divorce rate. The place is a disaster. Catholic Europe is dying because it has lost its soul. And it is too lost to even know that St. Benedict gave it a soul and that the new pope, Benedict XVI, is Europe's last, best hope to restore that soul."
Winfried Roehmel, director of the press office for the Archdiocese of Munich, said that about one-third of Germany is nominally Catholic. But he said fewer than 13 percent attend Mass with any regularity.
''It is a very slow, creeping decay. When the sun is shining, as it has on Europe for so long since the war, people feel they don't need God," explained Roehmel.
In Ireland, amid the rapid change that has come with unprecedented economic prosperity in the past decade, few dispute the notion that the edifice of Catholicism is in danger of cracking along its foundation.
The Rev. Brendan Hoban, a priest in a rural parish in County Sligo and author of the book ''Change or Decay: Irish Catholicism in Crisis," said the country's economic gains have come at a cost.
''Material prosperity has struck us like lightning in the last 10 or 15 years," Hoban said. ''We are a modern and prosperous country, and many Catholics no longer find their faith useful."
''We have a tremendous challenge trying to fix that, to find connections, to forge liturgies that will draw people in, and to write our homilies in a way that we inform people about the world they live in," he said.
At the Most Precious Blood parish in Dublin's Cabra West, parishioners over age 30 say they remember when the church, which seats 1,700, was packed for all four Sunday Masses. There were about 75 -- including only five children -- at the 11 a.m. Mass at Most Precious Blood on a Sunday last month.
''There were fierce crowds coming back then, the message was clear: come to Mass or go to hell. Well, that doesn't work anymore," the Rev. Thomas McCarthy said after the service, as a trickle of parishioners filed past, pulling their coat collars up against the chill of the rain-swept day.
Still, he is able to view some of the changes positively. ''Now the churchgoers are more mature, more reflective," he said. ''They're coming because they want to. That is a good thing. It is a smaller community, but one that believes more deeply."
Priests and social commentators say the flock has left the church because the Irish rebelled against what they saw as its suffocating hierarchical structure. Those who were drifting away were pushed further away by dark revelations of sexually predatory priests across Ireland.
''Back then, you'd have this church packed," said Anthony Keogh, 58, who was attending Mass with his two grandchildren at Most Precious Blood, where he said he has been a parishioner all his life. ''But not anymore, not after the scandals, not after the way the church handled them."
Down the street from the church, at the Cabra West Mini Market, a stream of customers was picking up the morning newspapers and most of them said they had not gone to church.
Tony O'Driscoll, 42, a truck driver, said that the local parish in Cabra West was hit hard by a 15-year-old case of clergy sex abuse that came to light in recent years. The allegations that surfaced pointed to a persistent complaint in Ireland and the United States: a church hierarchy that knew of priests committing crimes against children, but shifted the predatory priests from one parish to the next without turning them over to police.
''My son was an altar boy, and I'd wait for him every Sunday right outside the sacristy; I'd never take a chance of leaving him with a priest," he said. ''Finally, I realized if I felt that way about the priests, why were we going at all?"
To stem the tide will require a deeply spiritual and creative response, say priests and parishioners alike, and the church in Ireland is trying its best to come up with the formula.
Last month, on the fourth Sunday of Easter, which is also known as vocation Sunday, news that the Archdiocese of Dublin would not graduate a single priest from one of its seminaries rippled through the congregations.
At Our Lady Help of Christians on the Navan Road, a middle-class section of Dublin, the new archbishop, Diarmuid Martin, conceded in his homily that ''the relationship between the community and its parish has changed."
Last month, on the fourth Sunday of Easter, at a gospel Mass at the Church of St. Francis Xavier in Dublin, young men and women belted out rocking renditions of gospel arrangements such as ''Something So Wonderful" and ''Shackles." The church, which holds 1,000, was packed; hundreds stood in the back and along the aisles, swaying and clapping to the music.
The Rev. Brendan McManus, who presided over the Mass, said the gospel service was established to bring young people back to the church.
''We're trying to bring the message in a different way, through music, through a creative, dynamic liturgy, and through participation," he said after the service. ''This is the direction the church will have to take in Europe if it is going to address the problem.
''In the wake of the Celtic Tiger [economy], people are searching for something meaningful," he said. ''Many people realize that there is still a void there, even with all of the affluence and the consumer culture."
Solomon Ijigade, 20, an immigrant from Nigeria who sings in the choir, said, ''Catholicism has gone past that age where everyone was quiet, you know, and all serious. I think the church gets it now that you can be happy in church, and you can sing."