In the August 18, 2020 email update from the Gospel Coalition, editor Colin Hanson wrote, citing historian Philip Jenkins...
If a country has a fertility rate of 2.1 or fewer children per woman, the population will age and contract. And those contracting societies around the world, despite many differences, all tend to be secularizing rapidly. That includes the United States, with a rate of 1.7, which mirrors secular Scandinavia.Bottom line, the US is becoming increasingly secular and Africa is quickly becoming Christianity's global center. When you add in the rapid growth of Christianity in Asia and South and Central America, it proves the point that, far from a western religion, Christianity is the most diverse religion in the world.
You don’t need to debate causation or correlation in order to recognize Jenkins’s point. If trends continue, Western leadership in global Christainity will continue to diminish, at an even more rapid pace than Jenkins had first predicted back in 2002 with his seminal book, The Next Christendom. Current trends suggest that Africa will be home to more than 1 billion Christians within the next 30 years.