The novel tells the story of Valerie Alston, Tricia Houston, and their insignificant hustler boyfriend Kevin Rogers. When Valerie gets pregnant, she's convinced Kevin will take care of her. But when the baby is born and her mother throws her out of the house, Kevin abandons her. With no education and no way of supporting herself, Valerie finds herself facing a bleak future, while Kevin goes on to make the same promise to Tricia that he had once made to Valerie.

Refusing to simply accept her situation, Valerie begins the long road to changing her life for the better, first getting a GED and then a job. But the path in front of her is a rocky one, with many obstacles. This includes her need to reach out to Tricia who Kevin has impregnated and abandoned just as he'd disregarded Valerie's son. In extending her hand to Tricia, Valerie becomes her Sister's Keeper (Godly Sister).

But Valerie and Tricia are not the only ones who want to make changes. Kevin begins to realize how much he wants out of the petty hustler life. He leaves the neighborhood and starts over, eventually earning a college degree. He also finds God and joins the local church. However, the guilt of his past deeds still haunts him. Unable to ignore the harm he has caused; he reconnects with the women and children whose lives he has wrecked. The ultimate price Kevin pays is learning his absence as a father placed his daughter in the hands of a rapist.