Today’s post, as well as several posts to come, are excerpts from my new book, Can We Trust the Gospels? Investigating the Reliability of Matthew, Mark, Luke, and John.
Good sources are treasure for historians. Even when writing about an event they experienced personally, careful historians will consult sources beyond their personal knowledge. They’ll interview other witnesses. They’ll comb through published accounts. This is what responsible historiography always entails.
As I explained in chapter 3, at least two of the Gospel writers were not eyewitnesses of Jesus. The other two, Matthew and John, may well have been among Jesus’ inner circle, but we can’t be positive about this. What we do know for sure is that at least one of the evangelists made up for his lack of direct knowledge of Jesus by carefully collecting and utilizing historical sources. We know this because Luke tells us right up front.
The Gospel of Luke begins with a prologue similar to something an ancient historian would have written:

Since many have undertaken to set down an orderly account of the events that have been fulfilled among us, just as they were handed on to us by those who from the beginning were eyewitnesses and servants of the word, I too decided, after investigating everything carefully from the very first, to write an orderly account for you, most excellent Theophilus, so that you may know the truth concerning the things about which you have been instructed (Luke 1:1–4).

We don’t know who Theophilus was, though apparently he knew Luke and was willing to receive instruction from him. Theophilus may have been Luke’s patron (financial supporter), perhaps a newer Christian who looked up to Luke. Our interest lies chiefly in the sources Luke identifies. Notice carefully what he claims:

1. “Many” have already “set down an orderly account” of the events concerning Jesus. The phrase “set down an orderly account” refers to writing a narrative. Luke consciously drew upon more than one or two written sources.
2. The events concerning Jesus “were handed on to us by those who from the beginning were eyewitnesses and servants of the word.” “Handed on” is the language of oral tradition. It conveys the intentional passing on of stories and sayings. “Eyewitnesses” are those who actually saw and heard Jesus in the flesh. “Servants of the word” are those who preached and taught. So Luke attests to a thriving oral tradition about Jesus which was passed on by preachers and teachers. Yet these were not just any old servants of the word. Luke paid particular attention to those who based their preaching and teaching on their own eyewitness experience of Jesus.
3. Luke decided to write his Gospel “after investigating everything carefully.” In other words, he read the “many” written accounts of Jesus studiously, and made an effort to sift through the relevant oral traditions. Luke claims to be a thorough historian who has done his scholarly homework.
4. What is the point of Luke’s effort? He writes so that Theophilus “may know the truth” concerning Jesus. The ESV translates a bit more literally, “so that you may have certainty concerning the things you have been taught” (Luke 1:4). Luke has written his Gospel, paying close attention to the sources at his disposal, so that the reader might have confidence concerning who Jesus was, what he did, and why he matters. The “why he matters” part is expanded in Luke’s second volume, which we call the Acts of the Apostles.

I’ll have more to say about the prologue to Luke’s Gospel later. For our present purposes, I am most interested in Luke’s identification of two sorts of sources for his writing: oral sources and written sources. Both of these, according to Luke, derive from eyewitnesses who were also teachers in the church.