Christianity will still be the most prevalent religion in the world in 2050, but not by much. A 2015 study conducted by the Pew Research Center -- using data on fertility, age, and life expectancy -- predicted that 31.4 percent of the world’s citizens will identify as Christians by mid-century, compared to 29.7 percent identifying as Muslims. By then, Muslims are expected to be the fastest-growing major religious group, increasing from 23 percent of the world’s population in 2010 to nearly 30 percent. The research also showed that nearly 40 percent of the world's Christians are expected to be living in sub-Saharan Africa by 2050, which will be an increase of almost 15%.
Forecasting faith around the world:
- The percentage of the world's Christians living in Europe is expected to decrease to about 16 percent by mid-century, down from 26 percent in 2010. In 1910, 66 percent of the world’s Christians lived in Europe.
- Christianity is expected to decline in America as well, from three-quarters of the population identifying as Christians in 2010, to about two-thirds of Americans by 2050.
- By 2050, the country with the most Muslims is expected to be India, although Hindus will still constitute a solid majority there. Currently, Indonesia is home to the world’s largest Muslim population.