The particular egoic patterns that you react to most strongly in others and misperceive as their identity tend to be the same patterns that are also in you, but that you are unable or unwilling to detect within yourself. In that sense, you have much to learn from your enemies. What is it in them that you find most upsetting, most disturbing? Their selfishness? Their greed? Their need for power and control? Their insincerity, dishonesty, propensity to violence, or whatever it may be? Anything that you resent and strongly react to in another is also in you. But it is no more than a form of ego, and as such, it is completely impersonal. It has nothing to do with who that person is, nor has it anything to do with who you are. Only if you mistake it for who you are can observing it within you be threatening to your sense of self.

Eckhart Tolle

from A New Earth: Awakening to Your Life's Purpose