Andrew Sullivan has reviewed Robert Wright's newest book, The Evolution of God. Essentially, Wright argues that religion has evolved in ways that mostly improve its doctrines and practices, make them less rigid and more reasoned, and bringing us closer to truth.
As Sullivan notes:

"Fundamentalism, in this reading, is a kind of repetitive neurotic interlude in the evolution of religion towards more benign and global forms. It’s not a linear process—misunderstanding, violence, stupidity, pride and anger will always propel human beings backwards just when they seem on the verge of progress. Greater proximity has often meant greater hatred—as one god has marshaled earthly forces against another. But in the very, very long run, as human beings have realized that religion is nothing if not true and that truth can be grasped or sought in many different ways, doctrines have evolved. Through science and travel, conversation and scholarship, interpretation and mysticism—our faiths have adapted throughout history, like finches on Darwin’s islands.
Wright’s core and vital point is that this is not a descent into total relativism or randomness. It is propelled by reason interacting with revelation, coupled with sporadic outbreaks of religious doubt and sheer curiosity. The Evolution of God is best understood as the evolution of human understanding of truth—even to the edge of our knowledge where mystery and meditation take over."