Us Vs. Them

The human civilization has always looked to killing as the ultimate problem solver.  Man killing man has become a custom, whether its a punishment, a resolution, a sacrifice, or a service to a leader, god, or any other religious masters.   So when a human is killed, all problems are found right?  No, not right, the killing of someone else can be the end of the problem sometimes, but it's always the end of everything to do with that person. Death is final, and there is no going back after someone is killed, even if the killing was a mistake.
    The justice system uses the death system, killing those who commit very serious crimes.  If someone has done something that bad, death is an easy way out.  They should have to pay for what they did, in jail, not by being killed.
  Genocides are another example of killings, but unlike the death sentence, genocides aren't technically a punishment.  Sure it's a punishment on an entire group of people, not for committing crimes, but for simply being who they are, believing what they believe, looking how they look and seeing the world how they see it.  Adolf Hitler and many others saw a reason to attempt to wipe out an entire race/culture/group through his feeling of superiorness.  He felt that he was so important and superior to others that it was his job to decide who belonged on this world and who didn't.
   In the Crucible, the people of Salem choose to execute all people who seemed to be witches, because in the bible it states that those who are involved in witchcraft must be put to death.  Many people were hung during the trials, for "witchcraft", but when it all comes down to it, only the strong survived during these witch trials.  Whether someone was killed or not really depended on their social standing; who they had to support them, the connections, and liability.
     This concept of "Us vs. Them", humans killing other humans is ridiculous.  Why is death so common in our world?  I believe that most deaths are committed by those who believe they are better than others, but no one is better than anyone else, everyone is equal.  A world without killing?  would be a world of fear, not that it isn't already, but still, killing people makes the weak feel stronger than they are, it makes them feel empowered and without the thrill to kill they'd feel unsafe and powerless.