"1 Inasmuch as many have undertaken to compile a narrative of the things that have been accomplished among us, 2 just as those who from the beginning were eyewitnesses and ministers of the word have delivered them to us, 3 it seemed good to me also, having followed all things closely for some time past, to write an orderly account for you, most excellent Theophilus, 4 that you may have certainty concerning the things you have been taught."
In this Prologue, we have:
People who have undertaken to compile a narrative.
Eyewitnesses who are also ministers (servants) of the word (message).
These eyewitnesses delivered the word to Luke and his community ("us" v. 2).
Luke looks into it, and
Makes a decision to write it also, (as it seems good to him to do so).
Luke is confident that his compilation of the narrative is able to produce certainty in a one Theophilus,
Who has already been catechized (taught). Luke wants to write his account in an "orderly" fashion.
The prologue of the gospel according to Luke offers what we might call an historic epistemology. But even so, the adjective "historic" builds a category not present in the mind of Luke, the author. For Luke, "knowing for certain" (v.4) is built upon eyewitness testimony (v.2) who "compiled a narrative" of the life of Jesus. Luke, therefore, stands in a line of people in a community who desired to put together the story of Christ as a real history which can be known with certainty. Luke gives us epistemology exemplar--he tells his reader(s) that what is written is as sure as the Yankees' high salaries.
This prologue is no ancient myth genre, and even if "Theophilus" is a metaphor for the general reader (the names means, "Lover of God"), that no more means the prologue is a-historical than it would be if one were to compile an account of the Detroit Tigers' 2006 race to the World Series by telling the tale to a general audience addressed as "Tigers Fan." Of course, no one names their child "Tigers Fan" (although someone in Holland MI named his son after computer software back in the early 2000's), but the point is doubly taken, because if it is true that "Theophilus" is a metaphor, then the referent of the metaphor adds to the epistemic motive in the Prologue because a metaphor always has a real, space-time referent. So, "Theophilus" can mean either one particular person by that name, or it refers to any person who "loves God," the latter of which presupposes the idea of God's existence, power & authority, love and involvement in history even more so than if it were one person whose mother named him as such because she too, believed these things about the existence and nature of God.
Theophilus has been catechized (Gk. κατηχήθης, katechethes) i.e. instructed in the life of Jesus of Nazareth, the story Luke is about to tell. Already knowing the story, Luke desires to make Theophilus' knowledge more certain, and not only more so, but "certain."
For Luke, revelation has an epistemic thrust that is stronger than word of mouth built on eyewitness testimony. Luke himself, it is safe to assume, was not with the disciples during the life and ministry of Jesus, but, he sees his own writing as a "good thing to do," which is a moral judgment: there is wisdom and goodness and an ethical "oughtness" that is especially justified in his own mind to formulate a reproduction in script, and this action is far superior to the oral tradition Theophilus and company already have. It may be the case that those who desired to compile a narrative attempted to write it, or perhaps they simply attempted to compile an oral tradition.
But Luke's epistemology is built on the concept of the written word, something eschewed not only amidst professional philosophers of the postmodern ilk, but also of a whole host of evangelical theologians, philosophers and apologists as well. The theory of knowledge is of course, capable of boring--boring hole in the brain through boring boredom as it bores and bores and bores. For some folks who "have to know" however, it's like boring for pretty stones in a gem stone mine.
So, we should ask ourselves: if in Luke's mind, written revelation is worth its weight in gold to carry our epistemological inquiries to the bank, why should we be skeptical of revelation as an epistemological authority?