I started this book with a good degree of enthusiasm. It promised a lot, but unfortunately it didn't live up to expectations. Karen Armstrong's idea was to look at how people's idea of God has evolved over the last 4,000 years. To make this ambitious undertaking manageable she confined herself to the three big monotheistic religions, Judaism, Christianity, and Islam, with only side-glances at Hinduism and Buddhism, which seems reasonable, given the huge mass of material she has to cope with. Actually, her knowledge of some of these other religions is less than profound; she says, for example, that the Buddha taught that all life is dukkha (suffering); this is a popular idea but is misleading. But even with this limitation in scope, I found her book to be disappointing.
She begins with the Old Testament, tracing how Yahweh evolved from a tribal deity, competing with rival gods, into a single omnipotent God. At first the Israelites did not think about God philosophically but by the time of Christ they had come into contact with Greek thought and were increasingly obliged to set their faith in an intellectual context. Turning to Christianity, she considers how the notion of the Trinity evolved, rather surprisingly, from the monotheism that Jesus was familiar with. The Christian doctrines of the Trinity and the divinity of Christ are notoriously incompatible with the uncompromising monotheism of Islam, and Armstrong's discussion of Islam is probably the best part of the book. She has read extensively on this religion and gives plenty of detailed information about the esoteric movements within Islam in the Middle Ages, such as the Ismailis and the Brethren of Purity. Next comes a rather sketchy discussion of mysticism in all three religions; this huge subject is compressed into a mere fifty pages. Then on to the Enlightenment, the Death of God, and the future of God (if any).
Perhaps writing a book of this kind was an insanely ambitious undertaking, but in any case, I don't think that Armstrong was successful. In part, this is owing to the pedestrian way she writes; her prose is lifeless and unrelieved by any touch of humour. You need to have a lively style if you are to sustain your reader's interest over 500 densely packed pages, and this she lacks. Time and again I found myself skipping; I felt I was being bombarded with facts but they didn't add up to a coherent picture. I suppose this book might serve as a work of reference, but a stimulating read I fear it isn't, and at the end of it I didn't feel I had gained any notable new insights.