The fastest-growing church in the UK is the Chinese church. But the most phenomenal development of the last century was the tradeoff from West to East. The West lost ground and the East gained all of that ground back for itself. Christian adherents in Europe and North America as a percentage of the world population dropped by more than half between 1900 and 2023 (from 21.9% to 10.5%), while the percentage of Christians in Asia, Africa, and South America increased from 6% to exactly 21.9% of the world population. Amazingly, the two world people groups had exchanged positions over the last 123 years.