Vatican City — As Pope Benedict XVI prepares to relinquish his office, church leaders planning for a new pontiff are sure to deliberate over one of his longtime goals: replenishing Europe's deserted pews.
From the start of his pontificate in 2005, the pope focused on the decline in Christianity across the Continent, saying religious faith had been pushed to the margins of public life in the church's historic home.
The pope aimed to reverse this trend by taking his message on the road in countries such as Germany, France, Spain and Italy, where many people are nominally Catholic but fewer actually practice.
Speaking before massive crowds, the pontiff took European leaders to task, saying they encroached on religious freedoms such as the right to display Christian symbols in public schools. He called on Catholics to defend their church customs publicly. Pope Benedict also launched a new Vatican department charged with finding ways to re-evangelize Europe and other regions where secular trends were spreading, including the Americas.
Vatican analysts say there is little doubt the next pope will pick up where Pope Benedict left off in his "new evangelization" mission to lure lapsed Catholics back to the fold, with secular trends tugging at the church's foundations in Europe perceived as a threat to the entire global flock.
"It's a safe bet that new evangelization will be a theme of the new papacy. The whole church is on board in seeing the desire and need to do it," said Jeremy Driscoll, a professor of theology and liturgy at the Pontificio Ateneo Sant'Anselmo in Rome.
Mr. Driscoll, who attended a world-wide conference on new evangelism that Pope Benedict convened in Rome last fall, said church leaders feel "a real sense of alarm" over Catholicism's decline in Europe.
At the end of the conference, known as a synod, the bishops issued a statement describing Europe as a land "marked by…aggressive secularization and wounded by past regimes."
Still, the bishops praised European humanism for "building a common good," noting that "today's difficulties therefore must not dishearten European Christians, but must be perceived as a challenge."
Europe has long been the sick man of Roman Catholicism's global flock. While European streets are lined with Christian architecture and history, many here now regard religious faith as a private matter.
Europe is the only region in the world where Catholicism is contracting. The number of Catholics fell 0.01% in 2010, according to the latest official church statistics, compared with growth of 0.21% in Africa and 0.07% in the Americas. With more than a billion Catholics in the world, those seemingly small changes are actually significant.
There are signs practicing Catholics face an even steeper decline. The rate of baptisms in Europe has fallen 6% in the past six years. Europe's Catholic priesthood shed 905 clerics in 2010, compared with an increase of 761 in Africa, according to the Catholic Church's Statistical Yearbook.
This decline has been accentuated by the Continent's economic downturn, which discourages cash-strapped families from having lots of children.
There also have been some laws that have acted as a curb on religion. In France, a historically Catholic nation where secularism has long dictated that religious belief shouldn't play a role in public discourse, measures have been taken to restrict public displays of religious faith.
In 2004, the government of then-President Nicolas Sarkozy banned religious symbols, such as crucifixes and Muslim headscarves, from schools and other public spaces.
His successor, President François Hollande, is pushing to legalize same-sex marriage, which the Catholic Church strongly opposes. Spain, once a stronghold of Catholic tradition, legalized same-sex marriage years ago.
For all that, there are pockets of Europe where the pope's message appears to have been at least heard. In a recent opinion piece written for Catholic newspaper The Tablet, Fredrik Heiding, a Swedish Jesuit who lectures north of Stockholm, said the Catholic Church is showing signs of life in heavily secular Scandinavia, where church attendance is reputedly among the lowest in the world.
Mr. Heiding estimates there are 282,000 registered Catholics in Scandinavia, and 31 priests preparing for the vocation. This represents a "small and steady—but not dramatic—increase."
Mr. Heiding said Catholicism has benefited here because "religion is nowadays part of the public sphere, whereas it was almost taboo only two decades ago."
He said there have been a series of initiatives under way to cultivate interest. One is the inauguration in 2010 of the Newman Institute in Uppsala, the first Catholic university in Sweden since the 16th-century Protest Reformation. It is run by the Society of Jesus and offers courses in philosophy, theology and cultural studies. Its theology degree is accredited by the state.