My latest book was published by HarperSanFrancisco on March 13, 2007. The puff piece in their catalog is calling it "the first essential religion primer and an argument for why religion must become the 'Fourth R' in American education." Sounds good to me, though I think of it more as an exploration of this simple question: How is it that the United States is one of the most religious places on earth but most Americans don't know anything about their own religions, much less the religions of others? I try to answer this question historically, looking back to earlier times when learning to read and learning about religion went hand in hand. But I also offer practical solutions to the problem of religious illiteracy today, including mandatory Bible and world religion courses in public high schools. Throughout I interpret religious illiteracy as a civic problem. How can citizens understand the war in Iraq without knowing something about Islam? Or debates about gay marriage, stem-cell research, and capital punishment without knowing something about the Bible? You may or may not like the fact that religion is rampaging into the public square, but as a matter of fact it is, so it makes sense to know something about it.