The plot is driven by the personal quest of Daniel, who lose his father and uncle to the Romans and is seeking revenge. Daniel wishes to help the bandit leader Rosh build an army to drive the Romans out of Israel; as the book continues, Daniel's hatred is tempered by his interactions with Joel and Thacia. Thacia in particular helps Daniel to understand more about his own emotions and the power of love instead of hate; she is a student of the preacher Jesus, who is not yet revered as the son of God.
When the Romans were defeated and the last of them had gone, he would come back. He would build a good house for his grandmother and Leah, and there would be plenty to eat, and a good life for them at last. And there would be no more giving way on the road and looking over their shoulders before they dared to whisper, but everyone would walk free.
(Speare, The Bronze Bow, Google Books)
Daniel's quest is stalled by his return to his childhood home and the necessity of taking care of his sister, Leah, who has suffered severe mental trauma. He balances his personal war with his shifting morality and loyalties, until he learns that Rosh is only working towards personal profit, not towards the cause of Israeli freedom. With his beliefs challenged and feeling himself at rock-bottom, Daniel finally accepts the teachings of Jesus into his heart, and embraces love; he cannot drive out the Romans by himself, but he can drive out his hatred and make the world a better place.