You may have heard about a recent study showing some pretty low levels of religious knowledge among Americans (here's one reporting of it with some links).
It's entertaining and, pardon the pun, a little enlightening to see that "Atheists and agnostics, Jews and Mormons perform better than other groups on the survey even after controlling for differing levels of education."
Hmmm...
Are the religious just being rationally ignorant?
Perhaps people don't really believe their religions as much as believe in them.