Karen Armstrong is a prolific writer and I have read several of her books. The latest book is "The Case for God". I found it an enjoyable read, but it hit on very similar themes as many of her other books. In fact I joked on my facebook page that a more accurate title would be "A History of God" But she already wrote that book about 15 years ago.
The book discusses several different view points of God through out history, starting with shamanism and polytheism, to monotheism, rationalism, and the death of God. I already knew that our modern obsession with rationality and literal interpretation of texts was not shared throughout history. And I even had some inkling of the importance of ritual in human belief. However the one thing I learned was some of the history of the word "belief." Today it usually means some passive acceptance of a set of facts. It actually has similar roots to the word "love" and it used to imply action. This is one aspect that emergent type churches are focusing on. Believing (in the modern sense) in God is much less important than acting out love and compassion on earth.
She finally gets around to making her case for god in the epilogue. Her God is not the traditional God of Christianity, but is more mystery and compassion. I think she is correct that much of how we talk about God both inside and outside the church is idolatrous. She seems to view God as being a corrective for certainty. There is so much in this world that we do not understand and sometimes we can get carried away by our successes. She hypothesizes that the "new atheists" are so loud and certain, because they are mostly biologists and biology really hasn't hit the limits of what is knowable yet, unlike physics. It is an interesting idea and I know there are studies that say that physicists tend to be more religious than biologists.
If you haven't read any Karen Armstrong, this would be as good a book as any to start with and I think everybody should read at least one of her books. If you have already read any of her books, there probably won't be much to surprise you in this one.