In The Lost Gospel: The Book of Q and Christian Origins, Burton L. Mack hypothesizes a new gospel, Q (from Quelle, French for source), which he puts together by going backwards from the four (or five if you include Thomas) narrative gospels and comparing the materials that are identical enough that most scholars (on all sides of the question) claim Matthew, Mark, Luke, Thomas and John took from a contemporary source of Jesus's sayings. After abstracting Q from them, he then goes on to interpret why the five have other materials which are different from not only this source, but from one another. Obviously one of the reasons is that the four narrative gospels were written long after Jesus, or his contemporaries, were around to correct them, and many stories and rumors and speculation was available to choose material from. Q, on the other hand, consists of material from no later than the first 40 years of the various Jesus movements. There were many Jesus groups of which Q was only one. Each emphasized ideas important to themselves.
The Jesus of Q is not a political or religious reformer, but similar to a cynic philosopher and teacher. Teachers with followers/ students (like Socrates) were fairly common at the time. He does not claim to be God or the King of the Jews. He proposes a set of rules for a moral life. His followers are Jesus people, not Christ people (Christians). Q is a book of his sayings, his teachings, and there is no reason to study his biography; he is a man, a teacher; his words are what is important.
However, years later when each of the authors of the narrative gospels was putting together his material, each had various, and different, agenda in addition to merely writing down a few sayings; the reasons were more nuanced and complex. Burton L. Mack does not claim that any of them deliberately tried to change Jesus into something he was not, but that time and attitude had changed portions of the population's interpretations as to the significance of Jesus's message. Different groups emphasized different things.
Adding to this are Paul's views (who emphasized Jesus's death and mostly ignored his role as a teacher), many bishops' views, etc. Mack covers these differences in detail. He ends up claiming that a cynic teacher with no pretentions to universal greatness (based on the gospel of Q which was written during and very shortly after Jesus's lifetime), became bit by bit identified as the Messiah, the anointed or Christ, prophesied in the Jewish literature. Q shows the original; our own convoluted interpretation of a unity between Matthew, Mark, Luke, John, Thomas, and Paul (who do not interpret the same figure at all) shows our current Christian view.
In Organization, The Lost Gospel: The Book of Q and Christian Origins first explains how this gospel was "found" and put together. It then gives the complete text of the gospel and divides it into three parts, depending on when Mack believes it was written. Mack, a professor of New Testament at the School of Theology at Claremont, then provides a background explaining the social and cultural situation of the time and how it influenced the Q people. After that he shows how the Q material was passed down to, and incorporated by, Thomas, Matthew, and Mark (and from Mark to John and Luke). From there he gives details on how Paul and others created our Christian myth. Finally he explains how he feels this knowledge will effect our future beliefs. Mack thinks his hypothesis will change the church. However it is also possible, and even likely, the church will simply ignore it.
Conceptually the book is interesting; it does bog down in the many, many details, however. Anyone interested in the "real" Jesus could profit from reading this work, whatever his orientation to the situation is. Mack presents a human Jesus untouched by divinity; but the scholarly background he uses to present his view should be as useful to anyone who fully believes in the divinity of Jesus as to those who share Mack's own interpretation. The lengthy select bibliography would be useful to any scholars of this conflict as well.