It's the ego that causes separation

When I am full of ego, I become strong within myself. I become totally separate. So the more you like yourself as a person, the bigger your ego is. You say, "Well, I'm not supposed to like myself?". You're supposed to love yourself, but what self are we talking about? We're not talking about your body self, because that comes and goes. We're talking about your permanent self, that has always been here. And your permanent self is me, is you, is the world, is the universe, is everything. That's your permanent self.

- Robert Adams
Nonduality Highlights 3471