When we look at the world, our experiences and our relationships with a strong sense of Self, then we set up an us and a them automatically. When we hold our sense of Self up with pride at what we have done or what we know or who we know or whatever, we create further division.
If we can reduce our sense of Self, even to a level where we see ourselves as equal to others, we can live a more harmonious life. The eastern idea of there being no Self can be hard to agree with or even understand, but it is clear that a strong sense of Self causes problems.
Trying to think in terms of everyone being like brothers and sisters, much like many native peoples do, then we can cooperate more and develop wonderful, supportive relationships, and make the world a better place to be. The aim is to move from division to unity by getting ourselves out of the way.