A new report is revealing a troubling trend: Christianity remains the world’s top religion, Islam and agnosticism are outpacing the world’s top religion in terms of global growth. A recent Pew Research Center study examined data from 2010 to 2020, spanning 201 countries and zeroing in on seven religious demographics — Christianity, Islam, Hinduism, Buddhism, Judaism, lesser-known religions, and religious non-affiliation.

While the number of Christians worldwide increased by 122 million between 2010 and 2020, global population growth was faster, so the global share of Christians fell from 31% in 2010 to 28.8% by 2020. The vast majority of decline in Christianity occurred in the U.S., where the share of Christians dropped from 77% to 63%, but Europe and Australia also accounted for sizeable decreases in the Christian population. The only country to see any significant increase in Christian population share (a five-point leap over the decade) was Mozambique.

Islam, on the other hand, became the fastest-growing religion globally over the course of the decade. The number of Muslims rose by 347 million, which Pew Research noted is “more than all other religions combined,” ending the decade with two billion Muslims globally, just behind Christianity’s 2.3 billion. In 2010, Muslims accounted for 23.8% of the world’s population but made up over a quarter (25.6%) of the world’s population by 2020. But the world’s third-largest “religion” — and the second-fastest-growing behind Islam — was religious non-affiliation. These religious “nones,” as the Pew Research Center said, “were the only category aside from Muslims that grew as a percentage of the world’s population.” By the end of the decade, religious “nones” stood at 1.9 billion, accounting for nearly a quarter (24.2%) of the world’s population.

Joseph Backholm, senior fellow for Biblical Worldview at Family Research Council, said in comments to The Washington Stand that while “trends like this don’t have a single explanation,” he believes that the significant rise in Islam and relative decline in Christianity “is largely due to the fact that birth rates in majority Muslim countries are significantly higher than in majority Christian countries.” He explained, “Even if the current generation of young adult Muslims is having fewer babies than their parents, they are still having more than families in majority Christian countries. They have population momentum relative to the West.”

“The worldview of Islam is global and totalitarian, in the sense that it intends to conquer every part of society in every part of the world. Muslims have been playing the long game for a very long time and see birth rates and migration as part of their plan for global control,” Backholm continued. He added, “They are living out their worldview in very practical ways through their families. Islam also tends to have a higher retention rate than other religions as well. Perhaps because leaving Islam has huge consequences, most people born into it decide to remain in it.”

In 40 different countries, the share of Christians declined by at least five percentage points, and the number of majority-Christian countries fell from 124 in 2010 to 120 in 2020. Of note, Christians were no longer a majority in the U.K., France, or Australia by the end of 2020. While most of the countries that saw significant increases in Muslim population were already majority-Muslim, the number of majority-Muslim countries did rise from 49 in 2010 to 53 in 2020.

However, at least 35 countries saw an increase of at least five percentage points in religious non-affiliation. The most significant increases occurred in the U.S. (13 points), Uruguay (16 points), Chile (17 points), and Australia (17 points). The Pew Research Center confirmed that the increase in religious non-affiliation in the U.S. has yielded America the second-largest religiously non-affiliated population behind communist China and surpassing Japan.

Backholm commented, “The rise in those claiming they are religiously unaffiliated and the relatively slower growth in the Christian population is a function of a secularizing West that became so comfortable in its prosperity that it forgot it had any obligations.” He quipped, “Easy times create soft men, but the hard times created by soft men are certainly on their way, if not already here.”

“Scripture is clear that these things are cyclical. We turn to God — then away again very quickly. The West has turned away, and these numbers show that,” Backholm observed. He continued, “It’s all the more concerning because we are in a war whether we want to be or not, and if we are unable to build strong cultures through a commitment to the Judeo-Christian worldview, we will become vulnerable to whatever declares war on us, and Islam has certainly done that.”

Addressing the cause of these major global religious shifts, the Pew Research Center observed that the majority of decline in Christianity is due to Christians leaving Christianity, which is also the chief driver of growth in religious non-affiliation. In other words, both the worldwide decrease in Christianity and the global uptick in atheism and agnosticism were due to Christians abandoning their faith. For every new person who became a Christian between 2010 and 2020, 3.1 Christians left their faith, often becoming religiously unaffiliated, whereas almost the exact inverse was true of religious non-affiliation: for every one person who became religiously affiliated, 3.2 new people became religiously non-affiliated. The increase in the world’s Muslim population, however, was largely due to high birthrates, with religious “switching,” as the Pew Research Center called it, accounting for a low share of Islamic growth.