3.7a Global Religious Trends
Christianity is the largest religious group in the world (28.8% of the world’s population) (Hackett et al., 2025). Muslims are the second largest group (25.6%), followed by the religiously unaffiliated (24.2%) (see Figure 3.4).
Figure 3.4
Percentage of the World’s Population Belonging to Each Religion, 2020
Data based on Hackett, C. et al. (2025). How the global religious landscape changed from 2010 to 2020. Pew Research Center. https://www.pewresearch.org/religion/2025/06/09/how-the-global-religious-landscape-changed-from-2010-to-2020/ Copyright 2025 Pew Research Center.
The size of religiously unaffiliated people has grown as people leave other religions, especially Christianity (Hackett et al., 2025). Three people leave Christianity for every one who joins the religion. Buddhists and Hindus also have more people leaving these religions than joining them. Globally, people living in wealthier countries tend to be less religious compared to those in less affluent countries, which partially explains these trends.
Compared to other religions, Christians live all over the world (Hackett et al., 2025). Approximately 10% of the world’s Christians live in North America. However, this percentage increases to 34% when the Americas are counted. The rest live in Asia (12%), Sub-Saharan Africa (31%), Europe (22%), and the Middle East and North Africa (1%). In contrast, 99% of Hindus, 98% of Buddhists, and 59% of Muslims live in the Asia-Pacific region. Non-Christian religious groups are much less widespread around the world compared to Christians.