✝ 1st-century Roman Judea
Christianity
The largest religion on Earth, and the one losing the most people to switching — almost entirely in high-income countries.
Adherents
2.3bn
Share of world
28.8%
Median age
30
Net from switching
-73m
Where it is actually moving
Heavy net losses across Western Europe, North America, Australia and South Korea; strong net growth in sub-Saharan Africa, where the Christian population is now larger than in Europe.
Largest Christian populations
United States
208m · 62%For every American raised with no religion who has since joined one, about six raised Christian have left — the largest raw switching flow in the Western hemisphere.
Brazil
181m · 84%Catholic share fell from 92% in 1970 to about 57% today, but most of that moved to Evangelical Protestantism rather than out of religion entirely.
Mexico
114m · 88%Still overwhelmingly Christian, but the unaffiliated share has roughly tripled since 2000, concentrated in Mexico City and the northern border states.
Philippines
105m · 90%Asia's largest Christian nation, and the only Asian country where Catholicism has been the majority faith for over four centuries.
Nigeria
103m · 46%Africa's most populous country is split almost exactly down the middle, Muslim north and Christian south, and is projected to hold the world's third-largest Christian population by 2060.
Russia
102m · 71%One of the few countries with net movement *into* religion: Orthodox identification rose from about 31% in 1991 to over 70% after the Soviet collapse.
DR Congo
94.9m · 93%Traditional religions have moved from majority practice to under 5% in a century, the steepest folk-religion decline recorded in Central Africa.
Ethiopia
79.4m · 63%Home to Ethiopian Orthodox Tewahedo, one of the oldest continuous Christian traditions, established in the 4th century.
South Africa
51.0m · 85%African Independent Churches — locally founded, not missionary-planted — account for a larger share of South African Christians than any imported denomination.
Kenya
46.8m · 85%Church-to-church switching dominates: most Kenyan religious change is Catholic and mainline Protestant adults moving to Pentecostal congregations.
Germany
42.8m · 51%More than half a million Germans formally deregistered from a church in a single record year, a legally recorded act because of the church tax.
China
42.3m · 3%China holds the largest unaffiliated population on Earth — roughly 875 million people — alongside one of the fastest-growing Protestant communities.