Avatar: The Last Airbender, Book 2: Earth

Hugh:
--one big living organism, just like the entire world.

Aang:
I get how the tree is one big thing, but the whole world?

Huu:
Sure. You think you're any different from me, or your friends, or this tree? If you listen hard enough, you can hear every living thing breathing together. You can feel everything growing. We're all living together, even if most folks don't act like it. We all have the same roots, and we are all branches of the same tree.

Katara:
But what did our visions mean?

Huu:
In the swamp, we see visions of people we've lost, people we loved, folks we think are gone. But the swamp tells us they're not. We're still connected to 'em. Time is an illusion, and so is death.