Divergent Theme

 This book has a clear theme, as shown from the first sentence you read, on the cover: “One choice can transform you.” It’s a simple line, and yet it really pulls you in.

Tris has reached the age of sixteen, which in her world, means something bigger than it does to us. She lives in an era where everyone is divided into five factions. These factions are formed on the basis of virtues and traits their members have - Candor values honesty the most, Abnegation values selflessness, Dauntless value bravery, Amity value peacefulness and Erudite value intelligence. From birth, you are placed in the same faction as your parents, and at age sixteen, you have to choose your own.  

Although Tris was born into Abnegation, she chooses Dauntless. This could be considered her choice that will "transform her". Not knowing what she has gotten herself into, she must then face life or death tasks to see if she is brave enough to survive in Dauntless. As if the initiation processes aren't bad enough, she also has to worry about not being murdered by others who want to get rid of the competition, and that things are happening outside of the Dauntless area which could ruin to the world she knows.