The human idea of God has a history, since it has always meant something slightly different to each group of people who have used it at various points of time. The idea of God formed in one generation by one set of human beings could be meaningless in another. Indeed, the statement "I believe in God" has no objective meaning, as such, but like any other statement only means something in context, when proclaimed by a particular community. … When one conception of God has ceased to have meaning or relevance, it has been quietly discarded and replaced by a new theology. A fundamentalist would deny this, since fundamentalism is antihistorical: it believes that Abraham, Moses and the later prophets all experienced their God in exactly the same way as people do today. Yet if we look at our religions, it becomes clear that there is no objective view of "God": each generation has to create the image of God that works for it. The same is true of atheism. The statement "I do not believe in God" has meant something slightly different at each period of history. . .

Despite its otherworldliness, religion is highly pragmatic. We shall see that it is far more important for a particular idea of God to work than for it to be logically or scientifically sound. As soon as it ceases to be effective it will be changed--sometimes for something radically different.