The Recapitulation theory (http://en.wikipedia.org/wiki/Recapitulation_theory) states that “ontogeny recapitulates phylogeny—[…] a hypothesis that in developing from embryo to adult, animals go through stages resembling or representing successive stages in the evolution of their remote ancestors”.
I have the theory that the same happens with religion. When we are children we believe in fairies and magic beings behind everything we can’t explain, like the earlier human religions. As we grow old we move from polytheism to monotheism, and then to the idea of a creator less interested in every single little thing we do. And finally we go through Enlightenment, realizing that god is simply Santa Claus for adults.