The latest edition of the American Religious Identification Survey has found that 15% of Americans are not religious. This is up slightly from the 2001 survey, but is almost double the result found in 1990.
Educated people are less likely to be religious. Some think that religion is primarily a way of explaining the world, and educated people have learned another explanation. However, educated people are also more likely to be well off in every way - in their finances, their relationships, their psychic security. I think religious faith, for adults, is not primarily cognitive. It is not an explanation or set of ideas. Theology is for intellectuals. For most people, God is a source of confidence that their lives mean something, and a source of comfort that they are cared for in good times and, especially in bad.
When educated, secure people suffer serious setbacks, they often see that their cognitive idea of religion is not enough. For some this means a crisis away from faith. For others, like many of the no-religion people I meet, their crisis can be toward a real appreciation of the emotional roots of faith.
It is harder for rich, secure people to be religious. If you think you are doing well, are secure in your position, and that you got there by your own efforts, it is hard to feel gratitude to God. When bad things happen, it is easier for people to see how much we rely on the protecting hand of Providence.
Rich, secure, educated people who are religious typically do not think they achieved their lives on their own. The feel blessed and are grateful for their blessing which they do not deserve.