Who is God?

Is there some sense of God that all religions share? How has the identity of God changed over the millennia? Morgan Freeman embarks on a journey from the birth of monotheism in Egypt and Israel, to India, where Hindus worship millions of gods. He travels from a Houston megachurch to New Mexico where a Navajo girl communes with her divine ancestors. And, with the help of a neuroscientist, he searches for signs of God in his brain.