We don’t know what’s happened out there since they put us in here, or how many generations have lived and died since they did. We could be the last people left.
-- Tris (Chapter 7 paragraph Page 44)

Importance: This quote underscores the thought that everyone in the group is having about going beyond the city gates. They could be entering into a whole lot of nothing on the other side. Tris tells them that it really doesn't matter what might possibly be out there because there is nothing left for them on the inside of the gates. Here, readers see Tris taking a leadership role. The next day, when Evelyn passes her new rules, Tris and the others realize that going outside of the gate is their only real option, now.

I take a deep breath. I’m not sure where that swell of desperation came from, but now that I’ve acknowledged it, it...
-- Tris (Chapter 8 paragraph Page 54)