when students (esp. evangelical students) talk about the message of the New Testament, they usually mean Paul. And when they mean Paul, what they mean is Romans and Galatians. Their understanding (or sometimes lack of undestanding) of these two epistles often becomes the centre of not only Paul, but of the entire New Testament. Hebrews, Matthew, Revelation, and Luke-Acts are all forced into a Pauline framework.
Christian Origins shows us the real diversity of the early church. You only have to compare the Johannine literature, Luke-Acts, and Paul to see that the saving significance of Jesus was expressed in different (I did not say contradictory) concepts, categories, and terms. Approaches to the law were diverse and pluriform as Christians struggled (in every sense of the word) to understand how the law-covenant was to be understood and followed in light of the coming Jesus/faith (cf. Gal. 3.23). A study of Christian Origins opens our eyes to the reality and goodness of diversity, so that Christians can learn to differentiate between convictions and commands, and discern between the major and the minor doctrines of Christian belief. I would also add that, despite this theological breadth to the early church, there was still unity within diversity, a unity apparent in the common kerygma of the early church. While there was diversity and complexity in the early church, it was never a free for all, and the desire to discern between true and false expressions of belief were part of the Christian movement from the very beginning. That leads us to New Testament Theology and rather than priviledging Paul to supra-canonical status (and Romans and Galatians and hyper-canonical), we should listen to each corpra on its own terms and to the issues to which they speak.