"Strange as it may seem, the idea of 'God' developed in a market economy in a spirit of aggressive capitalism," Karen Armstrong asserts in her fascinating work A History of God. Armstrong considers herself a "historian of ideas," and with this broad view she gives a compelling account of the correspondences among Judaism, Christianity, and Islam, and the historical, philosophical, intellectual, and social developments through the ages that both shaped them and were shaped by them. Religion is "highly pragmatic," Armstrong finds. Any particular idea of God must work for the people who develop it. Consequently, as the times have changed, so have our ideas about God. "Understanding the ever-changing ideas of God in the past and their relevance and usefulness in their time," she says, "will help us to develop a new concept for the future." Today an increasing number of people have difficulty with the idea of a God that behaves as a larger version of themselves. Armstrong sees this as inevitable, and welcomes believers to a notion of God that "works for us in the empirical age."