text: Religion develops as a means to provide a grand explanation for *everything* (ie. weather, sources of food, death, interpersonal relationships, social systems, etc.).   It gives people a sense of security and predictability.  Sometimes the use of religion goes beyond predictability to the point of being used for control.  \n\nWhen one questions someone else's religious beliefs sometimes that triggers an insecurity that gets expressed as hostility.  If the questioning reduces control and individual has become dependent upon to maintain social or economic status the response can be extremely hostile.  \n\nThis is not to dismiss "religion" as a merely useful (for some) fiction.  Institutionalized atheism (China, and Stalin's Russia) has killed many people as well.  I guess you could just lump religion in with any ideology that attempts to assert itself on others through political or social means.