You are right without forgetting about the "I love everybody", "we love each other" and "love will make everything ok" ... we are all the same but just as a race or when we are born as you well also say, after that ... even twins do not think or believe in the same things if they are not adoctrinated the same, f.e. if they are separate the moment they born.

As far as I have seen unifications (or centralization can be called also) of something (culture, cities, language, etc) means more easy ways for to control humans.