Lubna Yaseen was a student in Baghdad when death threats forced her into exile. Her crime was to think the unthinkable and question the unquestionable—to state, openly, that she was an atheist.

Growing up in Hillah, a city in central Iraq, she developed an independent mind at a young age. “My mother is an atheist intellectual person, and she brought up me and my siblings to think for ourselves and to be open to anything,” she told me. Yaseen was particularly concerned about her teachers’ attitudes toward women. “I always asked why girls should wear a hijab and boys are not obligated to do so,” she said. Why would “God” treat the two sexes differently? She quickly learned the dangers of expressing these views: Her teachers often threw her out of their classes, and sometimes beat her.

In 2006, when Yaseen and her mother were driving home one day, al-Qaeda militants pulled them over and threatened to kill them for not wearing the hijab. Still, Yaseen’s desire to explore secular thinking grew at university. “I couldn’t keep my mouth shut. Whenever there was a conversation, I talked.” She started handing out leaflets on Mutanabbi Street, the heart of Baghdad’s intellectual life, and wrote about her atheist beliefs on Facebook. Her activism attracted further threats from fellow students and local Islamist militia groups, but she was determined to continue. “I believed in my rights to be who I am,” she said.

The tipping point came when Yaseen’s story caught the attention of the American TV host Dave Rubin, who featured her on his show The Rubin Report in early 2016. After the clip was released online, she faced a torrent of death threats and finally went into hiding. “I disappeared—I left everything. I had to be always on the run, changing places and disguises,” she said. “I couldn’t feel anything except that I would end up being killed.”

Yaseen would still be at risk if it weren’t for the actions of Secular Rescue, which helped her escape to California, where she is waiting for her asylum claim to be approved. The initiative, launched in 2016, is run by the Center For Inquiry, a U.S.-based non-profit organization that aims to promote secular values, such as scientific rationality and freedom of speech, with the support of Richard Dawkins and other prominent atheists.

“It’s really an underground railroad of sorts for non-believers in countries where simply expressing doubt about religious belief is a criminal offense or where it may lead to grave physical harm,” Robyn Blumner, the president and CEO of the CFI, told me.

Secular Rescue does not just face challenges abroad in militantly religious countries; due to some unnervingly resilient biases, implicit prejudice against atheists is still prevalent in ostensibly secular Western countries, making it difficult to raise the necessary diplomatic support there for people like Yaseen.

But in many countries across the globe, the danger of expressing non-belief comes directly from the state. According to a comprehensive report by the International Humanist and Ethical Union, a U.K.-based non-profit that aims to promote the rights of non-religious people, there are currently 12 nations in which apostasy (including atheism) can be punished by death: Afghanistan, Iran, Malaysia, Maldives, Mauritania, Nigeria, Qatar, Saudi Arabia, Somalia, Sudan, United Arab Emirates, and Yemen. Pakistan, meanwhile, threatens the death penalty for blasphemy, which may include expressions of atheism.

Even in states that ostensibly protect religious rights, atheists may have to fear repercussions from vigilante groups. In Iraq, for instance, the right to freedom of conscience is enshrined in the constitution, yet Yaseen faced regular death threats from fundamentalists and got little support from the police. “There is a mob mentality that sanctions violence against people who don’t conform on religious grounds,” Blumner said.

Paul Fidalgo, a spokesman for Secular Rescue, told me that government complicity is a particular problem in Bangladesh, which has seen the murder of at least 10 writers who had questioned the religious dogma since 2015. “We know there have been, and may still be, hit lists, issued by those who are trying to keep their hands clean, encouraging young radicals to slaughter secularists of their own volition,” Fidalgo told me. “And one of the worst parts is the callousness of the response from the Bangladeshi government. From the prime minister and other officials, we get several versions of ‘Well, they shouldn’t have been insulting religious beliefs.’ After one student was murdered, officials began to investigate the dead guy to see if he had written anything worth killing him over.”

When faced with these threats, many people are understandably reluctant to admit their religious doubts even to their closest confidants, making it difficult to gauge how widespread atheism actually is around the world. But there are signs that the numbers of atheists are sizable. A 2012 Win/Gallup International Poll, for instance, found that 19 percent of people in Saudi Arabia claimed not to be religious, with 5 percent identifying as convinced atheists—roughly the same proportion as in the U.S. That’s a surprisingly high number given the difficulties of exploring non-religious thought in this country, and the true figure may be greater; even if their responses remain anonymous, many non-believers may still have been reluctant to declare their religious doubts openly.

Mark Aveyard, a social psychologist in the United Arab Emirates, believes that some changing attitudes toward religion (at least in the UAE) may be linked to shifts in the way people are encouraged to think in education and at work. “They study or work in organizations where they’re encouraged to be bold, disruptive, innovative, creative, unconventional—with business, technology, entertainment, academics, etc. They’re rewarded for questioning the received wisdom.” Although many manage to compartmentalize these more critical attitudes, it has caused some to rethink their religion, Aveyard said. “So there are more youth now who question and doubt, but they do so privately.”

For non-believers like Yaseen who are more committed to expressing their opinions, however, the internet now provides a community and forum for the formation of an atheist identity. Arabic Facebook groups promoting atheism can reach tens of thousands of followers before they are targeted by “cyber jihadists.” (One popular tactic is to break into the account and post pornography, leading Facebook’s moderators to shut it down.) Blumner, meanwhile, points out that an Arabic translation of Dawkins’s book The God Delusion has reportedly been downloaded by more than 10 million people, with about 30 percent of downloads (3 million) coming from Saudi Arabia. “It shows you there’s a tremendous appetite for understanding religious doubt, for exploring religious doubt, for affirming religious doubt,” she said.

Some religious leaders and politicians are hoping to regulate atheism with increasingly fiery rhetoric and more stringent laws. Egypt, for instance, already criminalizes the act of blasphemy, leading to the recent conviction of a 29-year-old computer scientist for running a Facebook page on atheism. But in late December, the Egyptian government announced plans to extend these laws, so that disbelief itself would be criminalized, even if the person does not actively declare or promote atheism (although it remains unclear how this could be practically enforced).

Although some organizations like Amnesty International have taken up the cause of certain individuals, the CFI’s Secular Rescue was founded to tackle the broader global problem. The support it offers is largely diplomatic, financial, and legal: to pull strings with government agencies, organize the transportation of potential victims, and pay the costs of settling in a new country. Since 2015, it has helped save 30 people, including Ahmedur Rashid Chowdhury (also known as Tutul), who was chosen by Margaret Atwood for the PEN International Writer of Courage Award in 2016. The year before, he had suffered a nearly fatal machete attack by insurgents in Bangladesh, after which Secular Rescue helped his family to Norway. With enough funds, the group would hope to help many more.

Beyond creating these escape routes, Secular Rescue also campaigns for bodies like the UN to protect the rights of atheists to express their freedom of conscience. Blumner, for instance, recently visited the UN Human Rights Council to discuss mounting concerns in Malaysia, after an eruption of atheist persecution in August was sanctioned by the government. She says that the plight of non-believers is overlooked by politicians from ostensibly secular societies, meaning that activists working on behalf of persecuted atheists often struggle to garner the necessary support. “Part of the problem is that people don’t like atheists and it’s hard to protect a group you don’t like.”

This is even the case in the United States, where Blumner’s assertion finds support in a series of studies by the psychologist Will Gervais at the University of Kentucky, who has described atheists as “one of the most hated groups in the U.S.,” even as they face no state-backed persecution. His work has centered on a well-accepted measure of prejudice that tests how much people implicitly associate certain acts with representatives of a particular group.

In one early study from 2011, he found that people assume that atheists are more likely to commit immoral acts such as stealing money from a wallet left on the sidewalk, or failing to give the correct insurance information after a road accident. Indeed, of all the groups he measured—including Christians, Muslims, Jewish people, feminists, and homosexuals—only rapists were considered to be similarly untrustworthy. He has since shown that people are also more likely to implicitly associate atheism with incest, bestiality, animal torture, even murder and mutilation. Opinion polls, meanwhile, reveal that nearly 50 percent of people would rather that their children did not marry an atheist (compared to 34 percent who declared that they would be disappointed if their child married a Muslim).

“People have these strongly negative reactions to atheists,” Gervais told me. Strikingly, these views were not limited to religious participants in his studies. “Even our atheist participants seem to intuitively think that serial killers are atheists.”

He emphasizes that these associations are probably learned, and even if you don’t go to church, you may still be exposed to lingering cues in our culture that encourage that distrust. “We have had millennia of religious influence,” he said. Nor are these biases restricted to the U.S. In 2017, Gervais demonstrated that they are shared across many countries usually assumed to embody secular values, including the U.K., the Netherlands, and the Czech Republic.

It’s worth noting that people turning away from religion in the West may also feel threatened by the people in their community, and given the widespread bias against atheism—among the religious and non-religious alike—it’s not surprising they sometimes fail to report their fears. Maryam Namazie, founder of the Council of Ex-Muslims of Britain, has described a “tsunami of atheism” in the U.K., with many living in fear of reprisals from their religious community. “There are many cases where ex-Muslims have gone to the police and not received any support at all because the problems aren’t taken seriously,” she told the Independent.

Increasing the acceptance of atheists in the West—and concern about their plight in the West and elsewhere—may be a battle in itself, one that must be fought in tandem with the battle to sustain an “underground railroad” that rescues atheists from physical harm.

Yaseen, for her part, told me that she is still trying to heal from her experiences, but that they have ultimately made her more determined to share her story and build awareness of the dangers facing atheists in countries like Iraq. “I hope my voice can be heard, so Western communities can open their eyes to what’s going on, and build a safer place for people like me.”