Christianity is declining in Europe. According to the most recent Pew poll, only 71 percent of Europeans still identify as Christian, though 81 percent were raised in the faith. Most are non-practicing. Among the young, the situation is worse. About 55 percent of young Europeans aged 16–29 identify with no religion, according to a St. Mary University study.

As Christianity has declined, European politics has secularized. Christian democratic parties have lost their distinctive religious identities and become generic liberal or conservative parties. At the same time, secular Green and Socialist parties have increased their percentage of the vote.

But in recent years, this political secularization has enjoyed a notable, if perhaps superficial, reverse. The rise of Islamist terrorism has made once-fringe conservative parties stress their Christian identity. The League in Italy, the National Rally in France, AfD in Germany, and Vox in Spain, among other parties, are appealing to Europe’s Christian roots to counter what they see as an imperialistic form of Islam. These parties focus more on cultural identity than faith, though they have formed alliances with genuine believers. Rémi Brague has called this political form of Christianity “Christianism.”

One of Christianism’s leading proponents is Thierry Baudet, from the anti-establishment and anti-E.U. Dutch Forum for Democracy. He insists that Europe must acknowledge its Christian heritage. “Our new generations walk through our cities like strangers, they have no idea what even Easter or Christmas truly mean, or what all those stories in those beautiful stained glasses or churches tell,” he told me.

Santiago Abascal, the leader of Spain’s conservative and anti-establishment Vox party, also laments how Europe’s institutions continually discredit their Christian roots. “They tell our young to forget any link with the past,” he said. “A civilization that forgets its past is condemning its future . . . You can travel the streets of London, Paris, or Brussels to understand that multiculturalism has no reason to exist, except to serve the interests of the most powerful.”

Francesca Donato, a Member of the European Parliament for Italy’s League party, blames Pope Francis for not defending Europe’s Christian identity. “Often, when immigrants arrive illegally, the Church offers to host them,” she said. According to her, this amounts to preferential treatment for migrants and neglect of those in Europe who need the same kind of assistance. “Jesus talked about helping your neighbor, so we should start by helping those close to us.”

Some of these populists see Christianity as a mere element of Europe’s cultural identity. Others genuinely believe and practice the faith. In today’s political climate, these two forces are coming together. The genuine believers are cooperating with non-believers.

Abascal, for instance, is a practicing Catholic. Matteo Salvini, leader of the League in Italy, has held up the rosary at his rallies, but insists that he is not a “good Catholic.” Baudet is also not religious, but is sympathetic to Christianity.

While many Catholic leaders, including Pope Francis, have been openly hostile to populism, others are open to this alliance. Cardinal Müller, the former prefect of the Congregation for the Doctrine of Faith, recently argued that a politician who “symbolically holds up the Rosary is more to be trusted than one who literally takes down the Cross of Christ.” Marcello Pera, an atheist philosopher who once co-authored a book with Pope Benedict XVI, has told his fellow secular Europeans that “we must call ourselves Christians.”

Christian leaders hope that this alliance will lead to a genuine renewal of faith in Europe, but the more secular populist leaders may have something else in mind. They do not oppose Islam with Christian traditionalism. Rather, they fight Islam’s “illiberal” values by appealing merely to what they see as Christianity’s more “liberal” values—those compatible with a secular worldview.

For example, Salvini appeals to “values of liberty and Christianity” when speaking against traditional Islamic practices. During his rally at Milan’s Duomo Cathedral before the 2018 election, he said: “It’s evident that the fanatical interpretation of the Quran is incompatible with our values of liberty and Christianity . . . as a father, I want to recall how in schools some Muslim mothers are prohibited from learning Italian and working, and girls are prohibited from doing sports or going to birthday parties with other boys.” He then added that the veil and burqa were an “unacceptable” form of submission for women.

Of course, Christian leaders agree with Salvini’s criticism of Islam’s oppressive aspects. Liberty is not opposed to Christianity, though an all-encompassing ideological liberalism certainly is. But if populist leaders only use Christianity as a tool for opposing Islamic illiberalism, Europe will once again be a faithless society after it overcomes the threat of radical Islam. This use of the faith risks making Christianity a superficial element in these populist parties rather than their actual raison d'être. Whether Christianism will lead to a genuine revival of Christianity remains to be seen.

Alessandra Bocchi is an Italian freelance journalist.