If you are interested at all in historical Jesus studies and the issues surrounding them, you will definitely want to consider checking out James Dunn's new book. It's serves as an excellent, succinct, and readable introduction to the basic issues of historical Jesus studies, while offering Dunn's own unique contribution to the discussion. The basic gist of Dunn's book is that much (in fact pretty much all) of the work done by various scholars in search of a "historical" Jesus has failed to take into account some important factors that would have shaped the earliest Jesus traditions. There are two which stand out to me as being the crux of the book's arguments.
First, Dunn argues that Jesus life and teachings made an impact on his disciples that was faith-creating. The first disciples would have remembered Jesus words and actions precisely because of the impact he made on their lives. Therefore, the Jesus tradition as we now have it does not begin with the post-Easter faith of the disciples, but with the initial impact Jesus would have made on the lives of his hearers. As Dunn states, "Only the Jesus whom we can see and hear through the influence he had, through the impact he made on his first disciples, as evidenced by the traditions that they formulated and recalled, only that Jesus is available to the quester." (34)
Second, most questers have failed to seriously take into account the oral nature of the culture Jesus lived and taught in. This is because the quest has been carried out in a literary culture whose basic assumptions about the transmission of knowledge and ideas have been shaped by the printed word. Therefore, most questers have failed to understand the way knowledge is preserved and passed on in an oral culture. Dunn lists five distinctive features of oral tradition, the most important, to my mind, being that of its communal nature.
Given the impact he had on their lives, Jesus disciples would have formed communities gathered around his teachings and actions. These communities would have preserved, recalled, performed and celebrated the teachings and actions of the one who had so impacted their lives. The communal nature of this recollection would serve as a check against any radical innovation, as the community would operate within a "horizon of expectation" concerning what Jesus said and did. The community would be familiar with the teachings and deeds of Jesus, and would recognize anything that did not broadly fit with this tradition. Thus there would be an entire core of material that would be recognized as characteristic of what Jesus actually said and did.
What this means, in short, is that before any of the gospel accounts was ever written down, there was a well attested to, substantial body of material concerning Jesus teachings and actions that would have gone all the way back to the first disciples whose lives were so powerfully impacted by Jesus. It would be these traditions that the Synoptic gospels arose from. Therefore, there is good reason to believe that the traditions found in the synoptic gospels provide us with a reliable account of what Jesus said and did. Variations in details of the different gospels, far from being an insurmountable problem or embarrassment, would simply reflect the different emphasis of those who performed the tradition in varying communities. The recognized core of the tradition would remain the same in every community.
In my opinion, Dunn's book provides an excellent introduction to historical Jesus issues and an excellent argument for the reliability of the gospels that actually makes sense of the gospels as we now have them. It also explains in a simple, common-sensical way why the life and teachings of Jesus would have been preserved at all. Jesus made a faith-creating, life changing impact on those who knew him, an impact that continues to affect the course of human history, even down to the present day. In the words of Dallas Willard, "I think we finally have to say that Jesus' enduring relevance is based on his historically proven ability to to speak to, to heal and empower the individual human condition. He matters because of what he brought and what he still brings to ordinary human beings, living their ordinary lives and coping daily with their surroundings."