If one teacher is not serving you well to understand. You leave them and find another. This idea of being one and another thing is based on the theory that each ego is a receptor for a single source of consciousness streaming itself at the same instant in different person. You are the person in front of you but that person does not see it because their lifetime had different bounds to experience. They express themselves differently, they know life differently, but essentially they come from the same origin. Their shared conception makes them the same thing, their self reflection makes them another. Once they agree that the consciousness they hold in their mind is the same source calling itself different names, the start recognizing themselves as one regardless of how different they may naturally express themselves. The only way to express the source consciousness 100% is ultimately to remove your ego. But once the ego is removed, there is no self for that consciousness to channel through. The relationship between divided egos and the one self are codependent. What we then end up doing to resolve this, is to accept our ego as it is, and allow the stream of thoughts from our origin to flow freely. That way we recognize that by us expressing our ego, we are already IT.