Christian decline can mean several different things: fewer people identifying as Christian, a smaller Christian share of the population, lower church attendance, or declining membership in particular denominations. The most comparable recent worldwide data comes from Pew Research Center’s analysis of religious composition between 2010 and 2020.
This article now separates demographic evidence from theological reflection. The ranking below is based on change in Christianity’s share of the total population, not on assumptions about the spiritual condition of individuals.
Countries with some of the largest documented declines
Pew found substantial declines in the Christian share of the population across many countries. Among the largest decreases highlighted in its 2025 global report were:
| Country | Change in Christian share, 2010–2020 |
|---|---|
| Australia | about −20 percentage points |
| Chile | about −18 percentage points |
| Uruguay | about −16 percentage points |
| United States | about −14 percentage points |
| Canada | about −14 percentage points |
Pew uses a five-percentage-point threshold when discussing “substantial” country-level change because national sources and survey methods differ, making false precision undesirable.
Several countries lost Christian-majority status
By 2020, Christians were estimated to make up about 49% of the population in the United Kingdom, 47% in Australia, 46% in France, and 44% in Uruguay. Each had been Christian-majority in 2010. Across the world, Pew counted 120 Christian-majority countries and territories in 2020, down from 124 a decade earlier.
Disaffiliation is an important driver
In many European and other Western countries, the decline in Christian identification is closely connected with people who were raised Christian later describing themselves as religiously unaffiliated. This process does not occur at the same pace in every age group or country, and it should not be confused with a simple decline in population.
The religiously unaffiliated category also grew substantially in countries such as Australia, Chile, Uruguay, and the United States. Yet “unaffiliated” is not a synonym for atheist; it includes people with a wide range of beliefs and spiritual practices.
What demographic decline does not prove
Population statistics cannot measure the depth of a person’s faith, the quality of discipleship, or the future of a religious tradition. They also cannot show that every church in a declining country is shrinking. Migrant congregations, evangelical churches, Orthodox communities, Catholic parishes, and new Christian movements can follow different trajectories within the same national setting.
For broader context on the tradition itself, see our overview of Christianity.
