It seems to me that as soon as any nation becomes settled enough to try to bottle Christianity as their own cultural experience, that is when God will rearrange the world. Not allowing Christianity to be bound to any one culture is essential to the spread of the Gospel. While all other major religions are still primarily concentrated in the area of their origin, the focus of Christianity in the world has shifted many times -- Palestine to Mesopotamia, Europe to the U.K. and U.S. and now booming in Africa and Asia among other places. The reason is that the Gospel transcends culture. It enhances and unlocks the full potential in the culture of it's adherents rather than destroying it and/or attempting to replace it. Obviously, certain aspects of the culture will inevitably be changed. What I mean is that an Asian or Latin American person does not have to become Europeanized or Americanized (or whatever the case may be) to embrace the Gospel.
I have decided to call this phenomenon the "Tower of Babel Syndrome". We Christians have a built in tendency to journey only so far before we settle on the "plains" of our own "Shinar". That happens when we start to believe that we have gotten all that we need from God and we can handle the rest. We are content to blend just enough of the "God ingredient" with our lives/culture to make it pleasant but not uncomfortable. Of course, we will call God in if we think we need something, but otherwise we are busy building our own monuments. We need to tear down these towers, regardless of how grand or "religious" they may appear and embrace the everlasting Kingdom that God is building in us, with us and all around us.