An atom has both positive and negative particles, as well as neutral ones.  If any one of those particles is missing, we wouldn't have atoms, which make up everything in our world.  Just as the atom has opposing charges within it, so does our society with different ideas and beliefs.  In an argument, you have two different sides, as well as a neutral position.  We have many different religions in our world.  In many places, people can live side by side with people with different beliefs.  Even though they don't agree with each others' beliefs, we still call that peace, because they aren't going to war over it.    In some cases, there are wars over their differences in religious beliefs.  Conflict appears in many different forms.  War is an extreme case.  Having absolutely no conflict is an unrealistic goal.  To me, world peace means not solving your problems with violence.  Peace is not a perfect world where everyone gets along, because argument is a natural human behavior.  Conflict is inevitable.  But at the same time, there is still peace.