A report by Pew Research suggests that while there are many more persons professing Christianity today, that number is simply commensurate with the extraordinary population explosion we've seen in the last century.
The number of Christians around the world has more than tripled in the last 100 years, from about 600 million in 1910 to more than 2 billion in 2010. But the world's overall population also has risen rapidly, from an estimated 1.8 billion in 1910 to 6.9 billion in 2010. As a result, Christians make up about the same portion of the world's population today (32%) as they did a century ago (35%).
Further, a shift has occurred in Christianity that, to many in the Anglican Communion at least, won't come as a tremendous shock.
This apparent stability, however, 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%). And 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 grown enormously in subSaharan Africa and the Asia-Pacific region, where there were relatively few Christians at the beginning of the 20th century.
The report also tackles the question of the number and distribution of Christians living in China - facts still difficult to ascertain.