Millions of Europeans have drifted away from the Church. Yet Christianity still shapes political arguments about immigration and Islam. France offers a revealing example.

A reader recently commented on my article about Christianity’s decline in France. He made a distinction that stayed with me.

Europeans, he argued, may reject Christian religious beliefs while remaining attached to the culture those beliefs helped create. He also doubted whether secular ethics could provide a stable replacement.

I thought about the churches scattered across European towns. Some still attract large congregations. Others serve a dwindling number of worshippers. Yet their buildings remain part of the landscape, whether people believe in God or not.

A French citizen might never attend Mass, reject the divinity of Jesus, and still regard a medieval cathedral as part of France’s identity. I can understand that attachment.

What interests me is how Christianity sometimes becomes a political identity among people who no longer practise it, particularly when the discussion turns to Islam.

France’s Religious Change Is Larger Than the Debate About Islam

In June 2025, Pew Research Center published estimates of religious affiliation around the world. It found that Christians represented approximately 46% of France’s population in 2020. France had lost the Christian majority it held in 2010.

Across Europe, Christians accounted for about 75% of the population in 2010. By 2020, their share was roughly 67%. The religiously unaffiliated population increased from about 19% to 25%, while the Muslim share rose from 5.3% to approximately 6%.

These are estimates of religious affiliation, not measurements of how frequently people worship. The main story is not Muslims replacing Christians. Religious disaffiliation has played a much larger role in the region’s changing composition.

France’s national statistics provide another perspective. INSEE’s 2019–2020 survey found that 51% of metropolitan French residents aged 18 to 59 reported no religion. Catholics accounted for 29%, Muslims for 10%, and other Christians for about 9%. These figures describe that age group, not France’s entire population.

I examined the demographic argument in my earlier article, France Is Losing Christianity. Why Does Islam Dominate the Debate? But the reader’s comment suggested another question: what remains of Christian identity when people no longer follow the Church?

Christianity Without Regular Worship

In 2018, Pew surveyed 24,599 adults in 15 Western European countries. It found that many people identified as Christian while attending services no more than a few times a year.

Some retained a belief in God, though not necessarily in traditional Christian doctrine. Others valued churches for their social work or their role in bringing neighbours together. Christian identity had changed without vanishing.

I recognise this in family life. People carry customs from parents and grandparents long after they stop accepting the beliefs attached to those customs. Christmas may remain a family celebration; a cathedral can inspire pride in someone who never prays inside it.

There is no necessary hostility toward other religions in such attachment. Yet it becomes more complicated when politicians use Christian heritage to distinguish who belongs to a country.

When Christian Heritage Becomes Political

Sociologist Rogers Brubaker examined European populism in 2017 and its language of civilisation. Some movements have framed Europe as a cultural community under threat from Islam, invoking Christianity as a defining inheritance.

A politician can defend Europe’s Christian character without demanding that anyone return to church. In such arguments, Christianity can function as a cultural boundary rather than a declaration of personal faith.

France’s National Rally and the Catholic Question

Political scientist Tobias Cremer studied France’s National Rally in research published in Party Politics in 2023. His analysis drew on interviews and other evidence about the party’s relationship with Catholicism.

Cremer found that Catholic heritage and French secularism could both serve as markers of national identity in the party’s approach to Islam. Yet its political programme did not consistently follow the teachings or priorities of Catholic institutions.

I find this tension more revealing than claims that France is becoming a Muslim country. A party can claim to defend Christian civilisation while remaining distant from the Church’s authority.

Not everyone who values Christian heritage shares the National Rally’s politics. Plenty of people protect historic churches and traditions without wanting to exclude anyone. The research shows something narrower and more useful: religious identity and religious commitment can move in different directions.

France Challenged Church Power Long Before Today’s Immigration Debates

There is a historical problem with presenting Christianity as the uncontested foundation of modern France. Republican institutions developed partly through struggles against Catholic political power.

The French Revolution challenged the Church’s privileged status. The 1905 law on the separation of churches and the state then established a framework of state secularism and freedom of conscience, subject to public-order rules. There are regional legal exceptions to the general arrangement.

A Catholic could remain Catholic. A Muslim could practise Islam under the applicable laws. A citizen could also reject religion. The republic’s secular inheritance matters just as much to French history as its cathedrals do.

Related debates over religious expression continue today. I have also written about Europe’s hijab debate and competing ideas of women’s freedom.

Can Secular Ethics Replace Religion?

Nicholas B. Taylor, the reader whose comment prompted this article, questioned whether societies can retain Christian moral values after abandoning Christian belief. The concern deserves examination.

Religious communities provide much more than doctrine. Congregations bring people together. They give older people companionship and provide practical help during illness or bereavement. When participation declines, some relationships can weaken.

But losing those social networks is not the same as proving that secular ethics have failed. People can value compassion without believing that Jesus was divine. Belief in God also offers no guarantee that someone will treat neighbours well.

Families, voluntary organisations and secular institutions can provide help outside religion. Whether they replace every social function of a church is another question.

Nicholas called the transition unstable. I would want to know exactly what he means. Falling attendance at community events, political disagreement and a decline in moral responsibility are different phenomena. They require different evidence.

Why Does Islam Remain So Prominent?

Pew’s 2018 research found that Western Europeans who identified as Christian, including many who rarely attended church, were generally more likely than religiously unaffiliated respondents to express some negative attitudes toward immigration and religious minorities.

Political ideology, education and contact with Muslim people also mattered. The study does not establish that Christian belief causes those attitudes. Most respondents across the region accepted Muslims and Jews as neighbours, and negative opinions were not universal.

Still, inherited identity can shape how public life is interpreted. A medieval cathedral may appear to a secular citizen chiefly as national history. A mosque may enter discussions about present-day migration or integration. Neither building tells us how the people who use it treat their neighbours.

The difference between familiarity and perceived newness can affect public debate. It should not determine who receives freedom of conscience.

France has also faced serious controversies over the treatment of Muslim citizens. See my earlier report, A Gunman Targeted Muslims in France. The Warning Signs Were Already There.

Europe Is Not One Religious Society

European countries do not share identical histories of church and state. In some Central and Eastern European societies, Christianity remains strongly tied to national identity. France has a particularly influential secular republican tradition. Britain and Germany have different religious institutions and political arrangements.

Church attendance, religious self-identification and attitudes toward immigrants therefore cannot be treated as interchangeable measures. Even within one country, Christians disagree about immigration, state secularism and the authority of their own churches.

What Is Being Defended?

The reader’s comment brought me back to a point I had not fully examined before. Christianity can lose followers while retaining cultural influence.

A town may restore a historic church. A family may observe Christmas. A party may invoke Christian civilisation. All three refer to a historical inheritance, but they express very different commitments.

I would not question a French citizen’s attachment to the Christian history of France. The history is real. So is the republican tradition that challenged clerical authority, and so is the place of citizens who follow other religions or none.

A French Muslim can be deeply attached to France without accepting Christian theology. Someone raised Catholic can abandon religion without losing any claim to national belonging.

I keep returning to the cathedral that still matters to people who no longer attend Mass. Preserving the building is understandable. Claiming that its history gives one group a stronger right to belong is a different argument.

A country can preserve its Christian inheritance without requiring every citizen to share that inheritance as a religious identity.