Islam Grows Fast, Christianity Slows, A Quarter of Humanity Says 'No Thanks' to Religion – Pew Study Finds

Christians remain the world’s largest religious population, but the increase in their global population from 2010 to 2020 was smaller than the increase in the population of Muslims, a study by Pew Research Center published on June 9 revealed.

The Christian population across the globe rose to 2.3 billion in 2020, while the Muslim population reached 2 billion, according to the study. But from 2010 to 2020, the Christian population increased by 122 million only, while the Muslim population increased by 347 million, the American think tank disclosed.

The growth in the number of Muslims worldwide is more than the increase in the population of all other religions combined, the Pew Research Center noted. The Christian global population fell 1.8 percentage points, to 28.8 percent, while the Muslim population rose by 1.8 percentage points, to 25.6 percent.

The center explained that the increase in the global Muslim population is largely due to their relatively young age structure and high fertility rate, two characteristics that result in natural population growth.

The growth of the Christian population declined in Australia, Belgium, Brazil, Canada, and France, the think tank said. It also noticed Christian decline in Italy, Spain, Poland, the United Kingdom, United States, and other countries.

The study also found the Muslim population declined in Oman, a predominantly Muslim country in the Middle East with 95 percent of the population affiliated with Islam as of 2023.

It also reported Muslim population decline in Tanzania, an East African country where Christians represented more than 63 percent of the population as of 2020.

The center also revealed that the number of Hindus rose by 126 million, reaching 1.2 billion in 2020. But the number of Buddhists decreased by 19 million, dropping their population to 324 million.

According to the study, the population of Jews worldwide grew by nearly a million, reaching 14.8 million in 2020.

According to the study, 75.8 percent of the world’s population identified with a religion as of 2020. The remaining 24.2 percent were religiously unaffiliated people known as “nones.” The religious “nones” were the third-largest group in the study, after Christians and Muslims.

The Pew Research Center revealed that the population of religious “nones” reached nearly a quarter of the world’s population in 2020. The number of religiously unaffiliated people rose by 270 million, reaching 1.9 billion across the globe, the center said.

“The growth of religious ‘nones’ is striking because they are at a ‘demographic disadvantage’ – their population is relatively old, on average, with relatively low fertility rates,” the center said. “However, unaffiliated people continued to grow as a share of the global population because many affiliated people around the world – primarily Christians – are ‘switching’ out of religion.”

The center noticed substantial growth in the number of religious “nones” in 35 countries, including Japan, Vietnam, Australia, Belgium, and Brazil. It also reported an increase in the number of religiously unaffiliated people in Canada, France, Italy, Spain, Poland, and other countries.

According to the study, China had the biggest number of religiously unaffiliated people, who represented 90 percent of its population in 2020. The United States had the second-largest number of religiously unaffiliated people, with about 101 million “nones” in the same year.

Japan had the third-largest number of religiously unaffiliated people, with 75 million “nones.” “Global change in the size of religious populations is the result of two primary mechanisms: religious ‘switching’ and natural increase,” the center said, noting that the latter is influenced by demographic factors like age structure, fertility, and mortality.

According to the center, religious disaffiliation was the main driver of the decline in the Christian share of the global population. Religious disaffiliation, primarily of people leaving Christianity, was also the main driver of the growth in the population of religiously unaffiliated people.