Near the end of the book, Daniel travels to see Jesus and deliver a warning about the local teachers and Rabbis, who are upset with the sermons and reinterpretations of religious law as Jesus preaches it. While there, he comes to terms with some of his feelings about his own life and his purpose in the world. Daniel has spent so much of his life fighting and feeling rage that he cannot see the possibility that there are other methods of rebellion, and that some of them might be more effective than brute force.
"Daniel," he said. "I would have you follow me."
"Master!" A great burst of hope almost swept him to his knees. "I will fight for you to the end!"
[...] "I would ask something much harder than that. Would you love for me to the end?"[...] "You tell people about the kingdom. Are we not to fight for it?"
(Speare, The Bronze Bow, Google Books)
This is the key epiphany between Daniel's original motivation -- revenge -- and the lesson that Jesus wants to teach him, that one must love his enemies equally to his friends. Otherwise, hate will fill the heart and destroy any possibility of future happiness. Daniel does not quite grasp it, but promises that he will try to understand, and at the end of the book, Daniel finally internalizes the lesson and embraces love instead of hate.