It may mean that if 2 or more races/people get along everything will be equal to them instead of being kept away by a race/people... that may be what it means but im not sure
Tris changes factions and has to come out of her comfort circle to find out her identity and who she really is. Tobias must come to find compassion apart from his strict attitude.
Think about it like this... Non fiction is a real story (George Washington crossing the Delaware) but Fiction is a made up story (George Washington cutting down a cherry tree)<span />