Aslan has two major purposes in Zealot. One is to present a historical picture the conflicts in the Holy Land at the beginning of the First Century CE. The second is to use the historical perspective and the gospels to tease out the historical figure of Jesus of Nazareth.
I thought he did an excellent job with the first purpose. Aslan makes the period come to life. The conflict between the Jews and the Roman overlords is well described as is the ambiguous role of the high priest and other wealthy Jews. I didn't realize that during the period there were numerous messiahs wandering the land healing the sick, performing miracles and claiming to be the Son of God. According to Aslan, the title Son of God referred to a ruler rather than the actual son of God. The people were so distressed under the rule of Rome that they were looking for someone to wrest their homeland from the grasp of the overlords.
The second purpose, to find the historical Jesus by searching the available documents,was less satisfactory. Aslan seems to have made a decision in the beginning that the gospels were primarily propaganda written to enhance the Jesus myth. In his analysis, he uses only the Synoptic Gospels and Q. He discarded John's Gospel feeling that it tracked Paul's view of Christ's teachings rather than the Jewish version. For the Jewish version, he relies on James' letter believing that Jesus' brother would have a clearer idea of what he stood for than the other gospel writers who hadn't known him.
I found the book very readable and would recommend it to anyone wanting to understand the political climate in the Holy Land before the destruction of Jerusalem in 70 CE. However, I would recommend taking Aslan's pronouncement about the historical Jesus with a grain of salt. Jesus is presented in a variety of ways in the gospels. Aslan's portray of a rabble rouser who had designs on becoming King of the Jews is one way to read the gospels and does make sense in light of the political situation, but it is only one interpretation. I recommend additional reading about the time and some of the scholarly work on the gospels before embracing Aslan's interpretation wholeheartedly.
I reviewed this book for Net Galley.