The bronze bow is reference in the book of David and initially Daniel, Joel, and Thacia think that the only thing that will bend the bow of bronze is force. The friends and many others want to forceably get rid of the occupying Romans.
But as Daniel discovers, love is the only way to defeat hate; he must accept the grace of Jesus, and follow him rather than false leaders like the zealot, Rosh. It is a long and difficult process. Daniel has a lot to be hateful about...the Romans crucified his father and his uncle. Indirectly, they cause his mother's death and his sister's "madness." His aging grandmother is unable to support the children, and is forced to sell Daniel into indentured servitude, which is little better than slavery. Daniel escapes and finds Rosh, who promises to oust the Romans from Israel and restore proper rule.
For a long time, Daniel clings to this promise, even though Rosh's actions are self-serving. But soon Daniel will meet Jesus, whose message of love and tolerance ultimately overcomes fear and hatred. Jesus shows Daniel that nothing will supplant love: not hatred, not the Law, not revenge. Only love will "bend the bow of bronze" and give Daniel what he wants: hope and peace, at least within himself, for his family, and for those he cares about.