Daniel C Dennett's Breaking the Spell: Religion as a Natural Phenomenon traces the growth of religion from folk traditions to its present-day position in global conflict.
It seems religion has always been with us, from witch doctors to cardinals, from ritual human sacrifices to suicide bombers. Yes, it seems that God has a lot to answer for. Except of course that . . . well he exists only as an idea, a meme, a cultural artefact that evolves according to society's needs.