The Giver (The Giver #1) by Lois Lowry

Life in the community where Jonas lives is idyllic. Designated birthmothers produce new children, who is assigned to appropriate family units; one male, one female, to each. Citizens are assigned their partners and their jobs. No one thinks to ask questions. Everyone obeys. Then community is a precisely choreographed world without conflict, inequality, divorce, unemployment, injustice.. or choice.
Everyone is the same.

Except Jonas.

At the Ceremony of Twelve, the community's twelve-year-olds eagerly accept their predetermined Life Assignments. But Jonas is chosen for something special. He begins instruction in his life's work with a mysterious old man known only as The Giver. Gradually Jonas learns that power lies in feelings. But when his own power is put to the test - when he must try to save someone he loves - he may not be ready. Is it too soon? Or too late?