Actually, it is estimated that Red China already has as many Christians in the house churches as there are in America.
Not that that diminishes us, I'm just saying that they're as big and growing.
Noted. Also, I mentioned proportion, because there are several nations, even a couple in Africa and Latin America, where the % of practicing Christians is very high. Still, on almost any poll about God, Christianity, or whatever, Americans are among the highest in the world.