I don't accept that we must be violent just because we have been throughout history. Violence, as everything, is a choice. Once we grow up and see that we are all a family, and remove the factor of greed from the equation by giving up money, we really have nothing to gain by acting hatefully towards other humans.
...snip...
people don't hate for nothing,
there is always a reason why someone is being hateful, hate doesn't just come from nothing
and hate is something that humans use to punish someone for his bad behaviour, for behaviour that did bad thing to another human being
when you can't take revenge and can't find an another way to punish someone for something that harmed you or your loved ones the only thing left is hate..
even if you get away with something hate makes you remember that there are consequences for shit you've done.