According to a comprehensive Pew study from 2010 to 2020, Christianity remained the world’s largest religion, but Islam saw the most growth.
Newsroom, June 10, 2025, Gaudium Press – From 2010 to 2020, Christianity remained the world’s largest religion, but Islam saw the most significant population growth, according to a comprehensive Pew Research Center study. The report, titled “How the Global Religious Landscape Changed from 2010 to 2020,” draws from over 2,700 sources, including national censuses, demographic surveys, and population registers. Data collection faced delays in at least 65 countries due to the COVID-19 pandemic, with some 2020 estimates only becoming available in 2024.
The study analyzed 201 countries, categorizing populations into seven religious groups: Christians, Muslims, Hindus, Buddhists, Jews, adherents of other religions, and the religiously unaffiliated, often referred to as “nones.” Over the decade, the global Christian population grew by 122 million to 2.3 billion, while the Muslim population surged by 327 million to 2 billion, outpacing all other groups combined.
Rise of the Religiously Unaffiliated
A striking finding was the growth of the religiously unaffiliated, or “nones,” who increased to 24.2% of the global population by 2020, making them the third-largest group after Christians and Muslims. Despite typically older demographics and lower fertility rates, which hinder population growth, the “nones” grew due to significant religious switching, particularly among those raised as Christians. The United States, with the second-largest unaffiliated population after China, saw many Christians disaffiliate, though post-2020 data suggests this trend may be stabilizing.
Shifting Christian Demographics
Sub-Saharan Africa emerged as the new epicenter of Christianity, hosting 30.7% of the world’s Christians by 2020, up from 24.8% in 2010. This shift displaced Europe, where the Christian share dropped from 25.8% to a smaller proportion due to widespread disaffiliation in Western Europe and natural population growth in sub-Saharan Africa. Historically, in the early 1900s, sub-Saharan Africa accounted for just 1% of global Christians, while two-thirds lived in Europe. Christians saw population share changes in more countries than any other group, growing significantly only in Mozambique, where their share rose by 5 percentage points.
Muslim Growth and Stability
Muslims, while achieving the largest global population increase, saw little change in their share of national populations, as growth occurred primarily in countries where they already formed the majority. High fertility rates were the primary driver of this expansion.
Jewish Population Shifts
The Jewish population also saw regional shifts, with 45.9% residing in the Middle East-North Africa region by 2020, surpassing North America’s 41%. This change was driven by Israel’s population growth from 5.8 million to 6.8 million, fueled by migration and natural increase.
Hindu and Buddhist Trends
Hindus, the fourth-largest religious group, grew by 12% to 1.2 billion, with notable expansion in the Middle East-North Africa region, where their population rose 62% to 3.2 million. India remained the primary home of Hindus, who maintained a stable 14.9% of the global population. In contrast, Buddhists were the only group to decline globally, dropping 5% from 343 million to 324 million.
The Pew report highlights a dynamic decade for global religious demographics, with Islam and the religiously unaffiliated driving significant growth, while Christianity and Judaism experienced notable regional shifts.
Raju Hasmukh with data Sources:
Pew Research Center, “How the Global Religious Landscape Changed from 2010 to 2020,” 2024.
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