Why is it that when we talk to God we’re said to be praying,” Lily Tomlin once quipped, “but when God talks to us we’re schizophrenic?” That line undoubtedly played well in Cambridge, Madison and Berkeley. But that was before Tanya Luhrmann’s book exploded like a Roman candle in the review pages of the New Yorker, the New York Times and the New Republic. National Public Radio’s Fresh Air also featured the author. Little wonder. Luhrmann has won three prizes for a previous book, as well as a Guggenheim Fellowship and membership in the American Academy of Arts and Sciences. She now holds an endowed chair in anthropology at Stanford University.