(RNS) — A new Pew Research Center study measuring the evolution of the global religious population shows Muslims are the fastest-growing faith group, followed by the religiously unaffiliated. Though it remained the world’s largest religion, the Christian population declined between 2010 and 2020.
Pew’s Global Religious Landscape study, released on Monday (June 9), is the second edition of a demographic report of religious groups, started in 2010.
“We look at the demographic characteristics of these groups, their age structure, how many children they’re having, how much education they have, because these demographic characteristics affect the future size of the religious groups,” Conrad Hackett, a senior demographer at Pew Research Center, told RNS on June 6.
The study focuses on Buddhists, Jews, Hindus, Christians, Muslims and the religiously unaffiliated, also known as nones. It also looks at “others,” which include folk and traditional religions, wiccans, Zoroastrians and more.
The report, which also analyzed those who switched religions, reveals how religious disaffiliation and natural population growth in certain regions influenced the global religious landscape.
The world’s Muslim population increased by 347 million people over 10 years — more than all the other religions combined — primarily due to natural demographic growth.
“Christians are the world’s largest religious group” (Graphic courtesy Pew Research Center)
“Muslims are having children at a greater number than Muslims are dying,” Hackett said. “Very little of the change in Muslim population size is a result of people becoming Muslim as adults or leaving Islam as adults. …