Philip Jenkins wrote a book in 2002 called The Next Christendom: The Rise of Global Christianity in which he described the changes in world-wide Christianity that were resulting in a shift of the Christian population from the North to the "Global South" -- Latin America, Africa, and Asia.
Jenkins has written a sequel to this earlier work called The New Faces of Christianity: Believing the Bible in the Global South and Stan Guthrie, a Senior Editor at Christianity Today has interviewed Philip Jenkins. One question and answer is quoted below:
"...Global South Christians are closer to the economic and social world of the Bible than many Western Christians. How does this affect their religious life?
Things in the Bible make more intuitive sense. For a long time in Europe, for example, it's been a very plausible defense to say, "These rules in the Bible are laid down for a totally different, alien society. We have to change with the times." But for many modern Africans, the Bible describes a world they can see around them. And that gives more credibility to the moral or theological content of the Bible. Also, food is a very strong element in the Bible, and we tend not to see that in a society where the main food-related story is an alleged obesity epidemic. ..."
This goes a long way to provide an explanation for the apparent orthodoxy of Christians in developing countries. My own impression has been that the cost of professing faith in many developing countries is high enough that there are few, if any, "cultural Christians". Jenkins' suggestion that people in the "global south" read in Scripture about lives and conditions that are very familiar to them makes a lot of sense. It also explains why the center of the Christian population is shifting into Latin America, Africa, and Asia.