Christians remain the largest religious group in the world and form the majority in all regions except the Asia-Pacific and the Middle East-North Africa. However, their share of the world population is declining, as large numbers of Christians around the world "switch" out of religion to become religiously unaffiliated, according to a Pew Research Center analysis of more than 2,700 censuses and surveys.
Between 2010 and 2020, the global Christian population grew by 122 million, reaching a total of 2.3 billion. However, despite this numerical increase, Christians' share of the world population declined by 1.8 percentage points, dropping to 28.8 per cent.
Why is there a global decline in the Christian population?
Religious disaffiliation is the main reason for the decline in the Christian share of the global population. The growth of the religiously unaffiliated is the result of large numbers of people, mostly Christians, switching into the ranks of the unaffiliated (overcoming that population's demographic disadvantages of an older age structure and relatively low fertility).
According to the report, for every person who becomes Christian, three leave the faith, mostly becoming unaffiliated. Christians have experienced the biggest net losses from switching (3.1 have left for every 1.0 who has joined). Most former Christians no longer identify with any religion, but some now identify with a different religion.
As of 2020, Christians were a majority in 120 countries and territories, down from 124 a decade earlier. Christians dropped below 50% of the population in the United Kingdom (49%), Australia (47%), France (46%) and Uruguay (44%).
Between 2010 and 2020, the global Christian population grew by 6%, rising from 2.1 billion to 2.3 billion. However, the number of non-Christians increased at a much faster rate, 15%, causing the Christian share of the global population to drop from 31% to 29%.
Regionally, the number of Christians declined in Europe and North America. Europe saw a 9% decrease, falling to 505 million, while North America recorded an 11% decline to 238 million. In contrast, Christian populations grew in all other regions, with the most significant increase in sub-Saharan Africa, where the number rose by 31% to 697 million.
Where did the Christian share of the population change the most?
In 41 countries, the proportion of people identifying as Christian changed significantly, by at least 5 percentage points.
This decline was widespread across regions but was especially notable in Europe and other Western or English-speaking countries, where Christian majorities have been steadily shrinking for decades. The primary driver of this trend is the high rate of Christian disaffiliation, people leaving Christianity in adulthood despite being raised in the faith.
Australia saw the sharpest decline, with the Christian population dropping by 20 percentage points, leaving Christians as less than half the population by 2020. Similar steep declines were observed in Chile (down 18 points) and Uruguay (down 16 points). The United States and Canada each saw a 14-point drop in their Christian population shares.
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