also see root of all evil The cause of most wars in human history. It tries to explain things that we once did not know with now defunct, retarded answers. Most religious people would blindly follow an old book, leader, document, etc... rather than even consider more modern, logical answers. In times now past, it tried to give people hope and understanding, but now it just causes false hope, wars, political unrest and the eventual destruction of human society.
Halo also showes us how religion will threaten to destroy all humans.