From Psychology Today
Atheism blossoms in developed countries but is virtually absent in poorer nations. One interpretation of secularization is that big government helps citizens to feel more secure and less in need of religious reassurance. In a new study, I have found the most compelling evidence yet for this possibility.
It seems that people turn to religion as a salve for the difficulties and uncertainties of their lives. In an earlier study of 137 countries, I found that belief in God was higher in countries with a heavy load of infectious diseases, making life difficult and uncertain. Moreover, fewer people believed in God in wealthy and well-educated countries where life is easier. Countries with a more equal distribution of income – and hence less social problems - had more atheists. Atheism was higher for countries with a well-developed welfare state (as indexed by high taxation rates).
None of this is very surprising. My trips to predominantly atheistic countries have illustrated to me how well different societies can function without religion. The fact that some have argued the U.S. "needs" religion to fulfill certain social functions is a sad commentary on our society, not an argument in favor of religion.