Avatar: The Last Airbender, Book 3: Fire

Katara:
You mean after all Roku and Sozin went through together, even after Roku showed him mercy, Sozin betrayed him like that?

Toph:
It's like these people are born bad.

Aang:
No, that's wrong. I don't think that was the point of what Roku showed me at all.

Sokka:
Then what was the point?

Aang:
Roku was just as much Fire Nation as Sozin was, right? If anything, their story proves anyone is capable of great good and great evil. Everyone, even the Fire Lord and the Fire Nation, have to be treated like they're worth giving a chance. And I think it was about friendships too.

Toph:
Do you really think friendships can last more than one lifetime?

Aang:
[Aang takes Toph's hand] I don't see why not.[Katara takes Toph's other]

Sokka:
Well, scientifically speaking there's no way to prove that-

Katara:
OH SOKKA JUST HOLD HANDS.

[Sokka keeps his face turned and grabs Katara's hand.]