I knew I wanted to read God is Not One: the Eight Rival Religions that Run the World and Why Their Differences Matter by Stephen Prothero, after I saw his appearance on The Colbert Report. I had also read Prothero's other book, Religious Literacy, and liked that one quite a bit.
God is Not One is a response to the religious pluralists who like to say "they are all just different paths up the same mountain of truth". Prothero's thesis is that they are different mountains altogether, because different religions make different basic assumptions and are seeking answers to totally different questions. He lays this argument out in the Introduction to the book.
I was a bit disappointed to discover, however, that after that Introduction the rest of the book just examines each religion and explains the basics everyone should know about it. It's a bit of rework of Religious Literacy - a great text for a comparative religion class, (oohh, an idea for adult education), but not a major continuation of the "different mountains" discussion.
But Prothero's style is engaging and understandable, reducing some complex theological concepts to simple terms and grouping ideas nicely. And his judgment of the most important religions is interesting: Islam first, then Christianity, then Confucianism. It went on to Hinduism, Buddhism, Yoruba religion, Judaism, Daoism, and "A Brief Coda on Atheism".
Unfortunately, I've only made it to Buddhism and it's overdue at the library. So this one will remain on my wishlist.