The headlines are filled with stuff like Atheists Outdo Some Believers (NY Times) or Atheists and Agnostics Know More About the Bible than Religious (National Public Radio).
But not so fast! It turns out that Atheists didn't really win, it was more like Christians lost. The atheist/agnostic category got the best score at 20.9 out of 32 questions. But look at how it really went down:
|White Evangelical Protestant||17.6|
|White mainline Protestant||15.8|
|Nothing in Particular||15.2|
I have a couple of theories myself. One is that it's merely a coincidence, a correlation rather than a causal relationship. Jews, Mormons and Atheists are better educated than the average American; in fact, religion goes down dramatically with higher education. It shouldn't be a surprise that well educated people know more than less educated people, even about the Bible. The fact that Jews, Atheists and Mormons know more is perhaps predictable.
But another possibility is that this is an example of the Anti-Rationalism Meme hard at work. When faith and reason collide, the Abrahamic religions claim that faith wins. Since education is the foundation of reason and rational thinking, it's natural that the more fundamental versions of Christianity are not big advocates of higher education.
Ironically, this leads to the rather embarrassing situation where Atheists, Agnostics and Jews know more about Christianity than Christians do!