A tide of immigrants from the Islamic world is altering Europe’s landscape. The continent’s demographic profile is changing thanks to relatively open immigration policies and much higher fertility rates among immigrant communities. And the continent’s religious profile could change as well; with old-stock Europeans becoming increasingly secular, some scholars posit that Islam could become one of the region’s most visible and practiced religious tradition in the coming decades. Projections by Eric Kaufman of the University of London predict that the Muslim population will comprise up to 15 percent of Western Europeans by 2050. Given that 25 percent of Europe is expected to be atheist or agnostic by 2050, this will give Islam 20 percent of the religious market, and that proportion would be much higher if market exit included people who may not be atheists or agnostics but reject religious identification.

But that is only half the story.

Scholars have generally assumed that Muslims seeking a better life in the West want Islam to remain a central part of their culture. They blame Europe and North America’s failure to build real multicultural societies for pushing new arrivals toward radical Islamist groups such as al Qaeda and Islamic State (also called ISIS). It is true that marginalization pushes some young Muslims to the brink of extremist fundamentalism. But radicals are few and far between, and there has been little scholarship on the average religious behavior of younger immigrants and second-generation immigrants raised as Muslims.

In truth, the West’s embrace of secular multiculturalism has created a groundswell of increasingly non-religious Muslims, though quantitative research is lacking documenting this trend. Simon Cottee’s The Apostates: When Muslims Leave Islam provides readers with a powerful depiction of this group. Cottee examines how Western secularism challenges Islamic thought in ways that lead some to abandon their faith—an outcome that is much more common than resorting to fundamentalism. Data from the General Social Survey in the United States show that 32 percent of those raised Muslim no longer embrace Islam in adulthood, and 18 percent hold no religious identification. Rates of defection could well be higher in Europe and Canada. The odds that a Muslim in the United States will embrace radical fundamentalism are almost certainly much lower, although we do not have good measures tapping Islamic fundamentalism in quantitative studies.

A banner calling for British Muslims not to vote as part of the Stay Muslim Don't Vote campaign is held aloft outside the London Central Mosque in London April 3, 2015. Suzanne Plunkett / Reuters Leaving the faith, however, is not simply a personal decision: apostasy comes with the very real threat of punishment. In many Muslim nations, so-called apostates are executed, and even the slightest insult toward the faith can result in torture, imprisonment, or both. “Honor killings” for leaving Islam are both commonplace and have even taken place in the West. A recent Pew study found that 64 percent of Muslims in South Asian countries and 41 percent of Muslims in Middle Eastern and North African nations support the execution of apostates. Unfortunately, we don’t know much about the fundamentalist attitudes of Muslims in the West, and, it would be difficult to uncover such attitudes in survey research given the social desirability bias against such views.

Cottee uses qualitative interview data from 35 ex-Muslims in the United Kingdom and Canada to examine their religious life histories, focusing on their transition from belief, to non-belief, and eventually to renunciation. Cottee recruited his subjects online from the forum of the Council of ex-Muslims of Britain (CEMB), an influential support group for those leaving Islam in the United Kingdom and Canada. By focusing on the life histories of his subjects, Cottee gets beyond the simple platitudes that crowd Facebook forums for ex-Muslims—“Religion poisons everything”—and takes a deep dive into how one exits a religious community that embraces harsh punishments for non-believers both in this life and beyond.

Even in dire circumstances, Muslims and ex-Muslims came together in peace.

begins with the case of a young ex-Muslim man, Irtaza Hussain, who committed suicide a little over a year after being interviewed for the book. The loneliness, despair, and rejection apparent during Cottee’s interview, as well as in an evaluation of the young man’s Internet postings and interviews with friends in the ex-Muslim community, are common among young immigrants, who face rejection from non-Muslim peers and limited opportunities for social interaction in their smaller minority communities. As one of Hussain’s friends put it “Irtaza was just like us, a young person growing up in an adopted country, with sometimes difficult situations at home, financial issues, problems with career and employment, loneliness, heartbreak, sometimes stress, frustration, depression, and despair.” Hussain’s rejection of Islam exacerbated these problems by causing conflict with family members and isolating him from most of his ethnic community. Cottee’s morose preface thus demonstrates the necessity of creating safe communities for ex-Muslims. It also demonstrates that such a thing is possible; Although the young man felt profoundly isolated and lonely, his secular ex-Muslim friends held a memorial service after his suicide. At the service, Hussain’s father spoke of his son’s life and of happier times. Even in these dire circumstances, Muslims and ex-Muslims came together in peace.

The Apostates

A woman and child arrive for Friday prayers at Woolwich mosque in Woolwich, southeast London May 24, 2013. Luke MacGregor / Reuters Many crises of faith, like the one Hussain suffered, begin with a set of internal and external quandaries. A young person will question the inconsistencies of sacred religious texts and seek clarification or guidance from family and religious leaders. Of those Cottee interviews, most wanted desperately to be good Muslims. For them, the answers they received from religious leaders were never satisfying enough, and the leaders often implored them to stop questioning their faith. In turn, the would-be apostates would study the Koran and Hadith even more diligently. But the more they learned, the greater their doubts became. Making the pilgrimage to Mecca failed to inspire faith in one subject, making her feel even less connected to Islam.

Several of Cottee’s subjects reported that their doubts about Islam and the existence of a God were further fueled by the “New Atheist” movement and secular scholars, such as Richard Dawkins and Christopher Hitchens, who were appealing both because of the authority of scientific critiques of religious myths, and philosophical and moral objections to Islamic prescriptions and proscriptions. Many of them reported regularly reading online materials and watching YouTube videos of other atheists and skeptics. Many of the young people named notable ex-Muslim skeptics such as Harvard Fellow Ayyan Hirsi Ali and Faith Freedom International Founder Ali Sina as helping them clarify their doubts and to understand their rejection of Islam in a way that Western atheists likely could not. Hirsi Ali has also called for a reformation within Islam—one that is inclusive of non-believers as well as the faithful. What is clear from Cottee’s work is that the atheist movement is finding converts among Muslims, and that figures such as Hirsi Ali and Sina are not simply anomalies.

Gender also plays a strong role in Muslims leaving the faith, with many of the book’s female subjects pointing toward Islam’s subjugation of women as the final straw. In fact, female ex-Muslims almost uniformly said that polygamy and Mohammed’s taking of a child wife, Aisha, were two items that led them to doubt their faith. The prospect of an arranged marriage, likewise, weighed heavily on women considering apostasy. Although both male and female interviewees reported considerable tension with family members, Cottee’s female subjects seemed more fearful of the prospect of family violence. And for women from the most devout families, renouncing the faith was not easily hidden, since the rejection of conservative Islam meant a refusal to wear the hijab.

Leaving the faith is one thing, but staying out is quite another.

For these young Muslims, the process of renouncing one’s faith often took a ritualized form, emanating from the prescriptions and proscriptions of Islam. For many, enunciating or writing a reversal of the shahada—a declaration of faith in Islam—was the first step. They rejected the notion of God, and denounced Mohamed as a prophet. For women, taking off the hijab was another ritual. Violating proscriptions on alcohol and pork sometimes came next for Cottee’s subjects, with sometimes hilarious results as ex-Muslims realized that they didn’t even like pork, or that ham needs mustard. For many of the ex-Muslims, their initial rejection of faith came with an overt hostility all things religious. But, eventually, most of Cottee’s subjects reported, their anger subsided; some were embarrassed by their previous hostility toward Muslims as a result of their rejection of Islam.

Leaving the faith is one thing, but staying out is quite another. Ex-Muslims must live with the consequences of no longer sharing beliefs and practices with friends and relatives who often actively try to bring them back into the fold. For many, talking about faith is off-limits. However, many other subjects deal with their decision by not telling their family and friends about it, confiding in only a few close friends or within online communities. Indeed, nearly half of Cottee’s subjects are “closeted” about their apostasy, and more than half have not told their parents or both of their parents. Still, impiety is difficult to conceal, however, particularly during Ramadan. While Cottee’s subjects have taken the leap into apostasy, many more European Muslims have secularized without renouncing their Muslim identity, as is clear with many of the siblings and friends of Cottee’s subjects.

What is striking about Cottee’s work is how familiar it is. Apostasy is not specific to Islam, and the experiences of these ex-Muslims are similar to those of anyone leaving a strict religious movement. Leaving the faith has both personal and social consequences that take an emotional toll. But it gets better. As apostate and secularized Muslim communities grow and ethnic Muslim communities become more integrated into Western societies in subsequent generations, social pressures against apostasy will decline. Further, international campaigns to increase tolerance and reduce racism and Islamophobia will spur integration. Rather than enabling radical Islam, embracing Muslim communities as part of the broader society will weaken radical religion and promote secularism and civil, rather than uncivil, religion.