Darrell Bock is Research Professor of New Testament Studies and Professor for Spiritual Development and Culture at Dallas Theological Seminary. He is an author of a number of books many of which I own on the historical Jesus and Luke-Acts. I asked Bock some questions related to recent discussions as related to his book and he gladly replied.
Was there such a thing as early orthodoxy in the NT period, and if so what were the defining features? (Or what was their essential unity?)
Yes. I think you can see it in the doctrinal summaries in our earliest texts. 1 Cor 8:4-6, 1 Cor 11:23-26; Rom 1:2-4, 1 Cor 15:3-5. plus baptism and the Lord' table show the core theology of Jesus' person and his death, as well as salvation. These show how Jesus' death for sin brings blessing in new life. For example, baptism is death to sin then alive to God (Rom 6). These texts are important because they come from the first century making them our earliest witnesses to what was believed.
Does a broadly defined early orthodoxy in the NT period have any theological implications for Christian's today?
Yes, it let's us know what early Christianity believed. It tells us what the hub of faith is in terms of content. Jesus' person and work stand at the core of this teaching.
How do we know the orthodoxy that "won out" was the legitimate heir of early Christianity? Or, why shouldn't we be Gnostics?
Orthodoxy has apostolic roots Gnosticism does not have. The teaching on creation is also different. Gnostics believed God did not create and the creation was bad. In contrast Christianity inherited it's view of creation from Judaism-- God created and it was good.
Do you think Walter Bauer's thesis is a valid model? That is, of heresy preceding orthodoxy and orthodoxy dominating through Roman control?
No, His theory has major problems. I wrote a chapter on this in my book, The Missing Gospels. His theory has problems in terms of overestimating the presence of heresy in several of the regions he mentions. Bauer did not argue that heresy preceded orthodoxy, but that it existed alongside of it and was more predominant in several regions of the early church. Only in the region of Edessa might the claim he makes be true
I will be exploring New Testament period diversity in a number of posts comparing an early Aramaic Christian preaching with that of the early Pauline preaching.