Speare writes historical fiction, using history as the skeleton for her plot and adding some real and some fictional characters and events to "flesh out" that history, making it more meaningful to the reader. The events of the Roman Empire as depicted in the novel are for the most part true, with some real names (Herod, Tiberius), and many real locations (Galilee, Nazareth, etc). The story relates to the struggle of the Jews to free themselves from Roman rule and their belief that a Messiah will lead them to this revolution. Jesus was not accepted as the Messiah by all for he preached about a Kingdom with a meaning not all who wanted the revolution understood. Again and again we see Daniel's frustration with Jesus not taking over the leadership of the revolt against the Romans. Through Josh, Speare quotes passages from the Old Testament to show this longing and deep religious belief of the Jews, and through Jesus, Speare paraphrases events and parables in the Gospels of the New Testament to show the different message Jesus brought. As for Rosh's role in the novel, he seems to be a man working for himself rather than the cause of the Jews as depicted in the Old Testament. Beyond seeking "an eye for an eye and a tooth for a tooth" in his revolt against the Romans, he seeks his own advantage by hurting the Jews he says he wants to free.
The story has everything to do with Judaism, Christianity, and the Roman Empire. The Jews hated and suffered under Roman Rule as is evidenced by the deaths of Daniel's uncle and father by crucifixion. The Jews were waiting for a biblically promised Messiah to free them from Roman rule. Most looked for a kinglike messiah who would lead an army to defeat the Romans. This is what Daniel saw in Rosh. They were bound together by their hatred of the Romans and worked as an army to defeat them. However, Rosh was not moral in the Jewish sense of the word. He did not follow the Jewish laws. He steals, lies and cheats.
Jesus represents the other side of the Messiah as presented in the Old Testament. He preaches that love is the way to gain the Kingdom of God, not war. He reaches out in love to those who are not Jews breaking the prejudices of Jews against gentiles. Unlike, Rosh, Jesus acts selflessly and keeps the spirit of the law as presented in the scripture. He heals the sick, gives to the poor, is kind to the needy, and acts as a servant in all situations. He shows that hate can never gain anything. At the end of the novel, Daniel sees that Jesus, not Rosh has the answer. The split between Rosh and Jesus represents the later split between the Christains and the Jews. The novel shows how they come from the same place but part along the way.