Now, the narrative sources--to use a baroque but hallowed phrase--that is, the accounts which are consciously intended to inform their readers, still continue to provide valuable assistance to the scholar. Among their other advantages, they are ordinarily the only ones which furnish a chronological framework, however inconsistent.As I read this I cannot help but be reminded of Rainer Riesner's observation that no historian of Paul's life or the course of the first Christian decades has ever been able to dispense entirely with the framework found in Acts. And with good reason. Try to construct a history of the church in those decades absent Acts. Or the gospels for that matter. Without these narrative sources we'd have practically no idea when to situate the epistles. It is only because we read in the gospels (and in 1 Tim. 6:13, which is at that moment actually functioning in a narratival fashion, as defined by Bloch) that Jesus died under Pontius Pilate that we can narrow his crucifixion down to a specific decade, and frankly apart from that and other references to contemporaries we would have no idea that Jesus is to be situated in the first century at all. That's of course why mythicists need to work so hard to dispense with any connection between the gospels and history: because it is precisely these texts that nail Jesus down to a real time and place.
Similarly, the single most important chronological "anchor" not just for Paul's life but for the decades following Jesus's life is the inscription, found in 1905, that allows us to date Paul's appearance before Gallio in Corinth to sometime between July 1, 51, and June 30, 52. This chronological insight is lost however the moment that we decide that Acts 18:12-17 is nought but fiction. And it continues. New Testament historiography has tended to stake a great deal on the Jewish War of 66-73 and the Domitianic persecution of the church in the 90s. Yet again the very occurrence of such events are known almost entirely from narrative sources. Or try to talk about Valentinus and Marcion and other significant figures of the 2nd century absent such sources. Etc.
Bloch notes that the narrative sources are valuable with regards to chronological framework, despite often being quite inconsistent. This, I think, is a crucial point. Due to the pernicious influence of a particularly virulent inerrancy New Testament historiography has tended to put far more emphasis upon chronological and other inconsistencies in our narrative sources than is probably helpful or healthy. Those given to Chicago-style inerrancy want to show that the sources lack any inconsistency at all, a quest that would make Don Quixote proud. Such persons adopt an all-or-nothing approach to the narrative sources: either all is consistent or none is useful. The problem is that many of their opponents adopt the same approach, the only difference being that where one chooses "all" the other "chooses" nothing. Neither allows the possibility that it might very well be the case that, yes, Paul did indeed appear in front of Gallio in 51/52, even as, for instance, everything that Gallio is reported to have said during that meeting is entirely a Lukan construction. Or Luke might get details of Paul's itinerary wrong even whilst depicting the overall sweep of the church's early missionary expansion with reasonable fidelity. Etc. So many, probably far too many, of our debates regarding history method are really engaged with disputing the Quixotism of inerrancy instead of dealing with the actual work of historiography.