The Pew Forum on Religion and Public Life has a religious knowledge quiz; you can take it here. I got 100; the average score, however, is 50. Some interesting, and somewhat troubling facts:
- Evangelical Christians do better than mainline Protestants.
- Church attendance makes almost no difference.
- Jews and atheists do better than Christians of any variety.
- Mainline Protestants know little about the Old Testament or religions other than Christianity.
- Christians know little about the history of their own faith. Few can identify central figures of the Reformation or the Great Awakening.

My brother scored 13/15, saying his answers came from watching Southpark and The Simpsons.