While Christianity remains the world’s biggest religion, Islam is the fastest growing.
The religiously unaffiliated population is also growing fast.
These are the key findings of a new Pew Research Center study measuring the evolution of the global religious population between 2010 and 2020.
“We looked 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,” explained Conrad Hackett, a senior demographer at Pew.
RAPID GROWTH OF WORLD’S MUSLIM POPULATION
The study focuses on Christians, Muslims, Hindus, Buddhists, Jews and the religiously unaffiliated.
It found the world’s Muslim population increased by 347 million people over the decade to 2020 — more than all the other religions combined.
This was primarily due to natural demographic growth.
“Muslims are having children at a greater number than Muslims are dying,” Mr. Hackett told Religion News Service (RNS).
WHERE MUSLIM POPULATION IS DOMINANT
“Very little of the change in the Muslim population size is a result of people becoming Muslim as adults or leaving Islam as adults.”
Muslims are largely concentrated in regions with high population growth like the Middle East-North Africa region, where they represent 94.2% of the population, and sub-Saharan Africa, where they represent 33%.
The Muslim population grew the most in Asia (16%) which is home to large Islamic populations in Indonesia, Pakistan and Bangladesh.
WORLD’S CHANGING CHRISTIAN POPULATION
Alhough Christianity remains the world’s largest religious group (29%) and the number of Christians grew over the surveyed decade, it declined by 1.8% due to larger population growth among non-Christians.
It steadily declined in Europe, North America, the Americas, Australia and New Zealand, Mr. Hackett explained.
It was down 8.8% in Europe and 10.8% in North America.
In the United States, the Christian population fell from 78.3% to 64% from 2010 to 2020.
In Australia, the United Kingdom and France, the Christian population dropped below 50% during that decade.
IMPACT OF FERTILITY ON CHRISTIAN REGIONS
Pew found that in addition to an increase in religious disaffiliation, the decline of Christianity in Europe (23%) can also be explained by low fertility rates and high death rates.
By contrast, Africa, where fertility rates are higher, is now home to the largest Christian population.
One-third of the world’s Christians live in sub-Saharan Africa.
They remain the majority faith in all regions except for Asia and the Middle East-North Africa.
RAPID GROWTH OF RELIGIOUSLY UNAFFILIATED
The global non-Christian population grew by 15% partly due to the growth of the religiously unaffiliated (24%) who are now the third largest group .
Despite an aging population and a lower fertility rate than the religious groups, the category has swelled over the surveyed decade because of religious switching.
For every adult raised non-religious who joined a religion, about 3.2 adults left the faith in which they were raised, the study revealed.
In North America, the religiously unaffiliated population increased by 13 percentage points between 2010 and 2020, exceeding 30%.
Asia is home to the largest religiously unaffiliated population with 78.3% — nearly all of them in China.
SMALLER RELIGIONS
Hindus represent just under 15% of the world’s population with most of them in India.
Buddhists are the only religious group that had fewer members in 2020 than in 2010 — declining by 19 million people over the decade.
The world’s Jewish population, the smallest religious group analysed in the report, grew by 6% in the surveyed period to around 15 million people — half of whom live in Israel.
