Loss and separation: listener question

In your book “Inside-out guide to life, unlimited”, pages 58, 59:It looks like when someone dies that they have gone. In reality, they have not gone anywhere because the Awareness and Love that they really were, is the same Awareness and Love that we are. The way we experienced them through Thought while alive, is still the same in death. As Byron Katie says, “No one can leave me.”… Whether he is physically here or not, his life lives for me, as it always did, in the Awareness that I make possible.… And that within this Awareness that we are, it is impossible for us to lose anyone, impossible to be separate.Query 
I still can’t get it that “no one can leave me”, that “it is impossible for us to lose anyone, impossible to be separate.” Can help?