>Meanwhile, there are many smaller groups who have a far brighter future, due to high birth rates and low attrition rates, but they are coming up from such a lo

>Meanwhile, there are many smaller groups who have a far brighter future, due to high birth rates and low attrition rates, but they are coming up from such a low base, it is going to take them many decades, even centuries, to overtake the incumbents. I would like to point out the fastest growing religious movement in the world was Pentecostalism. A movement that was limited to a few working class American churches in the early 20th century that has since exploded to 500 million followers across the globe, though this explosion is generally masked since Pentecostals are officially a sect of Protestantism and highly diffuse. The growth is best scene in Central America where countries that were almost universally Catholic two generations ago can be as much as 40% Protestant, which is almost entirely thanks to conversion to churches of the Pentecostal-Evangelical variety.