Patheos answers the question:

What is the Largest Religion in the World?

Group of people

According to data collected by the Pew Research Center, as of 2021, the largest religion in the world is Christianity. In 2015, the number of Christians who lived on earth comprised roughly thirty percent of the over 7.3 billion people currently alive. This means that, in 2015, there were about 2.3 billion people who identified as Christian. Of course, Christianity has thousands of denominations or sects; the largest of which is the Roman Catholic Church—which boasts membership of approximately half of all Christians. Eastern Orthodoxy, Anglicanism, Lutheranism, Methodism, and various other protestant denominations constitute some of the more than 2 billion people who consider themselves to be Christians. 


Some of the other world religions that have significant membership include Islam and Hinduism. In 2015, there were 1.8 billion Muslims and just over 1 billion Hindus. There are also about half a billion Buddhists on the earth today. In addition to Islam, Christianity, and Hinduism, no other religion constituted more than one billion people, though the Pew Research Center notes 1.2 billion people identify as unaffiliated, meaning there are over a billion people on earth who do not identify with a particular religious group. 


Christianity, Islam, and Hinduism have long been the largest religions in the world. and demographers don’t see that changing anytime soon. While it is common to lump all Christians, Muslims or Hindus together, as noted, each has many denominations, sects or communities within, and significant differences in practice and belief. In other words, an Eastern Orthodox and a Baptism worship very different from each other and believe some very different things about doctrine and sacraments. The same could be said of a Sunni, a Shia and a Sufi Muslim. The number of Hindu denominations and gods isn’t even known, and practice along with belief varies wildly from one Hindu to another. Thus, declaring Christianity as the “larges religion in the world” really needs to be clarified so that it is understood that that grouping of faiths called “Christian” look very different from each other, practice their faith quite differently, and believe a variety of things—including holding that other Christians are, in some cases, heretical in their beliefs or practices. Simply put, none of the largest religious denominations are unified in their belief or practices. 


All of that being said, Christianity is still considered the largest religion in the world by population, and there is not really another way that demographers, researchers, or scholars can calculate the size of a religious group. Part of what makes Christianity the largest religion in the world is the fact that more Christians are born than die in any given year, which means that Christians generally reproduce at a rate that keep their numbers up. In the five-year period before 2015, for example, the Pew Center estimates that 223 million babies were born to Christian women and about 107 million Christians died, which means that there was over 116 million more people born into Christian homes than who died during that five-year period. The reality of such trends suggests that Christianity will remain one of the largest religions in the world, even if at some point Islam passes it up based on its high conversion rates—something Christianity has struggled with in recent years.


Learn more about world religions here. 

3/23/2021 6:32:39 PM