Christians make up about the same portion of the world’s population today as they did a century ago. But that apparent stability masks a momentous shift. Although Europe and the Americas still are home to a majority of the world’s Christians (63%), that share is much lower than it was in 1910 (93%). The proportion of Europeans and Americans who are Christian has dropped from 95% in 1910 to 76% in 2010 in Europe as a whole, and from 96% to 86% in the Americas as a whole.

At the same time, Christianity has experienced enormous growth in sub-Saharan Africa and the Asia-Pacific region, two areas that were home to relatively few Christians at the beginning of the 20th century. The share of the population that is Christian in sub-Saharan Africa climbed from 9% in 1910 to 63% in 2010, and in the Asia-Pacific region from 3% to 7%. Christianity today — unlike a century ago — is truly a global faith. (See world maps weighted by Christian population in 1910 and 2010.) Read More

Russell Heimlich  is a former web developer at Pew Research Center.