Both YES and NO Many people believe that god created human beings and that he gave them “colors”. However human beings divide themselves politically, economically and socially. Those who kill others because of/in the name of god do not understand the holy book correctly, while those who continue giving his best to the world are living by the “rules” of god.
I don't think religion can be looked at as a "cause" for war. What causes war are the traits of human beings in general. Take away a humans natural capacity for aggression, greed and self-preservation and what you have left are his positive traits and his values which generally serve as the basis of our religions. I think religion is just something that people use to lift up their “suggestion” to war, it’s kind of like a fuel that people use to get an ethnic group started with the hate and war.