In December 2011 the Pew Forum on Religion and Public Life (Washington) issued A Report on the Size and Distribution of the World’s Christian Population. Some of the data were developed in collaboration with the Center for the Study of Global Christianity (South Hamilton, Massachusetts). The two institutions are responsible for the bulk of reliable statistical information on religion worldwide. They are directed, respectively, by Luis Lugo and Todd Johnson. I happen to know these two gentlemen quite well. They are the religious nose counters par excellence. Ask them how many Lutherans there are in Mongolia, and how many Buddhists in Finland, they will within a few minutes come back with reasonably accurate numbers.
While the broad outline of the situation has been known for some time, reading the sheer mass of figures in the Pew report is startling. The ongoing comparison is between the years 1910 and 2010. Apart from marking the beginning of a century convenient for comparison, the earlier date is significant in itself. 1910 marked the date of the World Missionary Conference in Edinburgh. It was attended by about 1,300 delegates (all Protestants—Catholics and Orthodox were not invited), most from Europe and North America. The conference (whose centennial in 2010 was celebrated by a series of events) is now seen as the culmination of the Protestant missionary movement of the nineteenth century, and as a prelude to the ecumenical movement of the twentieth. Its official theme was “The Evangelization of the World in This Generation”. The mood was triumphalist, the expectations grandiose. Yet I doubt whether any of the participants could have imagined either the size or the shape of Christianity a century hence.