Digby highlights a story on CNN that addresses this very issue. After quoting from the transcript, Digby writes the following:
I agree that it's a little bit odd that the vast majority of people in a country that prides itself as the most religious in the world can't name the writers of the gospel, but really, whose fault is that? The last I heard, there were tens of thousands of churches in this country. Is it too much to ask that they be in charge of religious instruction? Isn't that their specialty?
I know that many of the conservative mega-churches spend most of their time instructing their parishoners on Republican politics and holding Christian rock extravaganzas so they don't have time for actual religious teaching. Understood. But maybe they could send their kids to the mainline and liberal churches once a month so they can get some actual Bible teachings. With all the pressure on public schools to find a way to teach biology that doesn't offend the Christian Right, they just don't have the resources to spend on special classes about Biblical references in pop songs and presidents 'n stuff.
I'm sure there are many churches that would be happy to accomodate those who want their kids (or themselves) to learn about religion.
As always, Digby is right on the money, and all I can say is, keep preaching.