In 2003, British Prime Minister Tony Blair was asked about his faith during a magazine interview.  As Blair began to offer an answer, he was interrupted, cut off by Alastair Campbell, the prime minister's director of strategy and communications.

"We don't do God," Campbell said. " I'm sorry."

Campbell seemed to know, in the not-so-distant past of European politics, that any public mention of religion was a serious taboo.

This week, as top ecclesial and political leaders gather in Rome to discuss the future and identity of Europe, Vatican Secretary for Relations with the States Archbishop Paul Gallagher said that religion is no longer a forbidden subject in European politics.  

"The days when you could say 'we don't do religion' are over," Gallagher said.

"Many diplomatic services throughout Europe and elsewhere are now running courses, literally accelerated courses to make up time on religion," he said, explaining that political leaders are beginning to recognize that "the world is a very religious place."

Increase in religious affiliation worldwide continues to grow around the world, he said, explaining that this fact "brings with it a very big responsibility for believers." 

"I think we have to take that responsibility very seriously, and make sure that religion is making a positive contribution, and that religion, and if you want to say even the Catholic religion, is a part of the solution and not the problem."

Archbishop Gallagher spoke alongside German Cardinal Reinhard Marx at an Oct. 27 press conference on a major conference titled "(Re)Thinking Europe: A Christian Contribution to the Future of the European Project," taking place in Rome this week, drawing hundreds of high-level European Church and political leaders. 

Running Oct. 27-29, the conference is organized by the Commission of the Bishops' Conferences of the European Community (COMECE) in partnership with the Holy See, and will consist of a joint, constructive reflection on the challenges facing Europe.

Some 350 participants from 28 delegations representing all E.U. countries are in attendance, including high-level E.U. politicians and Catholic hierarchy, academics, ambassadors, representatives of different Catholic organizations and movements, as well as from other Christian delegations.

Responding to a question posed by CNA on the role religion can play in Europe given its Christian roots, Pope Francis' continuous call to go back to those roots, and the growing presence of Islam, Gallagher said he believes there is a growing awareness and recognition in the world of "the positive things religion does."

Although Europe continues to grapple with a high influx of migrants, Gallagher said,"I think we have to stick to principles.  If we believe in religions freedom, then it is valid for a Hindu, for a Muslim or anybody, as it's valid for a Christian."

The archbishop also said that, in his view, there is "often a great degree of misinformation and 'scaremongering' of the sizes of the Islamic communities around Europe." The Pew Research Center estimates that Muslims constituted 6% of Europe's population in 2010.

While Europe works to carve out a path forward, Gallagher said he believes religions will play "a positive role." This, he said, is first of all because "we do recognize that some of the liberal, secularist thought that was part of much of our societies, is not in good health either."

He said we have to "combat a lot of political correctness that exists within Europe," as well as the tendency "to kick religion into the private sphere and not to allow it to be part of the public debate."

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"This is something which we obviously have to work on, and it is a work in progress," he said. 

Also weighing in on the issue, Cardinal Marx, Archbishop of Munich, President of the COMECE and Coordinator of the Vatican's Council for the Economy, noted that 20 years ago many people thought "religion would disappear" from society. 

"That was the common conviction of many sociologists and politicians, that society will progress and religion will disappear; secularism." However, "that's not the case."

"Religions will be very important for the 21st century," he said, explaining that a key question conference participants will have to ask themselves on the role of religions is: "will they be an instrument of peace and dialogue, or of confrontation?"

For Christians in particular, the Second Vatican Council said the People of God, the Church, are "a sacrament of unity for all human beings," and not just those inside the Church. 

"We are not only for us, and the Pope is underlining this," Marx said. "We are not narcissistic, inside ourselves, we are part of a solution for all human beings."

"I do not see that the Church is 'less interesting' in the public world," he said, and stressed the need to continue pursuing a dialogue with Islam, which he noted isn't new to Europe.

"So for the future, I think the Catholic Church has to play a very important role to find ways of dialogue, ways of relating to this religion, which is very important for the 21st century and Europe," he said.

The cardinal said his greatest fear moving forward is not so much that religion will be ignored or eradicated, but that "it will be instrumentalized for other reasons, for political reasons. That will be perhaps the great fear for the 21st century."