How does one understand the New Testament without the Old? How do you separate systematic and Biblical theology when both are important? And a huge one for me: how are so many NT scholars so completely unaware of patristics? Yes, they may use a quote from Ignatius here and there, but I know a great many NT scholars who are in no way well-versed in Church Fathers. This seems vital to me! Historically, you can separate the two, but ideologically you cannot. The history of the ideas of the church is, in my most humble and uneducated opinion, quintessential for understanding Biblical studies. Or, as April Deconick has written about, how do we toss aside important information contained in these Nag Hammadi texts? Yes, I realize they're late and don't provide a great amount of historical information concerning Jesus, but they provide historical information concerning the beliefs of a particular subset of people. Why did they interpret the New Testament in such a way as to arrive at these beliefs? That's valuable, I think.
Immediately after posting this I went to Dr. Deconick's blog and she shares a similar conviction about the matter:
My third point was that most biblical scholars aren't interested in studying the NH documents because they are perceived to be late and therefore of no consequence to Christian Origins. The same is true, I suppose, for ante-Nicene literature in general. Not many biblical scholars take the time to become well-versed in much beyond the apostolic fathers.