The theme of the book "Divergent" by Veronica Roth is the danger of societal conformity and the importance of individuality.
In the world of "Divergent," society is divided into five factions based on their dominant personality traits: Abnegation, Amity, Candor, Dauntless, and Erudite. Each individual is tested at the age of 16 to determine which faction they are best suited for and must then choose whether to stay in their current faction or switch to a different one. The main character, Beatrice, or Tris, as she becomes known, is told that she is "divergent," meaning that she doesn't fit neatly into any one faction and possesses traits from multiple groups. This makes her a threat to the established order and she must keep her true nature a secret in order to survive.
Throughout the book, Tris grapples with the idea of conformity and what it means to be truly oneself. She is torn between the values of her upbringing in the selfless Abnegation faction and the freedom and self-expression offered by the daring Dauntless faction. As she gets drawn into the dangerous world of Dauntless, Tris begins to question the strict hierarchy and rules of her society and the true cost of conformity.
As Tris discovers, the factions are not as different as they appear on the surface and all have their own flaws and weaknesses. The supposedly selfless Abnegation faction is revealed to be just as susceptible to corruption and manipulation as any other group. Meanwhile, the supposedly fearless Dauntless faction is revealed to be controlled by a group of ruthless leaders who use fear and violence to maintain their power. Tris learns that true bravery and selflessness come from within and cannot be imposed by external forces.
The theme of individuality is also explored through Tris's relationships with other characters, such as her love interest, Four, who encourages her to embrace her true self and not conform to the expectations of others. Tris also finds allies in unexpected places, such as the members of the Erudite faction who are disillusioned with their own leaders and the rigid rules of their society.
In the end, Tris must confront the corrupt leaders of her society and fight for the freedom to be herself. She learns that true strength and courage come from within and that it is essential to be true to oneself, even in the face of societal pressure to conform. The theme of individuality and the dangers of conformity is a powerful and timeless message that resonates with readers of all ages.