Central to [John] Crossan’s methodology is the dating of texts. This is laid out more or less fully in The Historical Jesus in one of the appendices. He dates part of the Coptic Gospel of Thomas to the 50s CE, as well as the first layer of the hypothetical Q Document (in this he is heavily dependent on the work of John Kloppenborg). He also assigns a portion of the Gospel of Peter, which he calls the “Cross Gospel”, to a date preceding the synoptic gospels, the reasoning of which is laid out more fully in The Cross that Spoke: The Origin of the Passion Narratives. He believes the “Cross Gospel” was the forerunner to the passion narratives in the canonical gospels. He does not date the synoptics until the mid to late 70s CE, starting with the Gospel of Mark and ending with Luke in the 90s. As for the Gospel of John, he believes part was constructed at the beginning, and another part closer to the middle, of the 2nd century CE. Following Rudolf Bultmann, he believes there is an earlier “Signs Source” for John as well. His dating methods and conclusions are quite controversial, particularly regarding the dating of Thomas and the “Cross Gospel”. The very early dating of these non-canonical sources has not been accepted by many biblical scholars.
In God and Empire: Jesus Against Rome, Then and Now (2007), Crossan starts with the presumption of reader familiarity with key points from his earlier work on the nonviolent revolutionary Jesus, his Kingdom movement, and the surrounding matrix of the Roman imperial theological system of religion, war, victory, peace, but discusses them in the broader context of the escalating violence in world politics and popular culture of today. Within that matrix, he points out, early in the book, that “(t)here was a human being in the first century who was called ‘Divine,’ ‘Son of God,’ ‘God,’ and ‘God from God,’ whose titles were ‘Lord,’ ‘Redeemer,’ ‘Liberator,’ and ‘Saviour of the World.'” “(M)ost Christians probably think that those titles were originally created and uniquely applied to Christ. But before Jesus ever existed, all those terms belonged to Caesar Augustus.” Crossan cites the adoption of them by the early Christians to apply to Jesus as denying them of Caesar the Augustus. “They were taking the identity of the Roman emperor and giving it to a Jewish peasant. Either that was a peculiar joke and a very low lampoon, or it was what the Romans called majestas and we call high treason.”