Political scientist Ryan Burge summarizes part of the sociological conversation about secularization and wealth at a national level:
If you take a course in the sociology of religion at any college or university, the professor will inevitably spend some time on what is known as secularization theory. This theory posits that as societies become more economically prosperous and obtain higher levels of education, the inevitable result is a movement away from organized religion and toward secularization…
The conclusion from this graph is clear: the more economic prosperity a nation enjoys, the fewer citizens of that country say that religion is very important. There are a few outliers, however. China is in the bottom left portion of the graph, which means that based on the country’s economic output it should be more religious than it currently is, with the same occurring in Hungary.
Obviously, both of those countries have a history that is closely associated with communism, which is the likely cause of their low levels of religiosity. On the other hand, the United States is clearly an outlier on this graph. It ranks as the most economically prosperous country in the dataset, but if it were going to be in the middle of the trend line, the overall level of religiosity should be very close to zero.
The takeaway lesson from teaching this in undergrad sociology classes is that the United States is unique in terms of religiosity. Then, the task of sociologists and other social scientists is to tease out why exactly this pattern holds for many industrialized countries and not others. Burge goes on to discuss one explanation from recent sociological research in the United States:
Taken together, the results from this sample tell a simple story: secularization is apparent for older generations of Americans, but for those born after 1950 there is no evidence that education leads to a decline in religious affiliation.
Of course, secularization is not just about wealth. As Norris and Inglehart argue, the more that governments or nations take on the role of providing existential security to residents, the less need residents have for religion.
Or, as a number of scholars have argued, the United States is an outlier for another reason: it has a unique religious market. Because of a lack of government involvement in state religion plus the protection for freedom of religion, religious groups have been free to compete. This competition leads to innovation and religious groups compete for attendees and resources.