The many sources for the historical Jesus.
Oral and written traditions in primitive Christianity.
Early Christian traditions, both oral and written.
(The secret gospel of Mark used to make this list, but not anymore. Its date of composition is too late, middle of century XX).
N. T. Wright writes on pages 423-424 of The New Testament and the People of God:
It seems to Wright that the evangelists may have had a great deal of information about the historical Jesus at their disposal. It seems to me that Wright is probably right.
On my first pass through this important book by Wright, as I was reading those very words above, two passages immediately sprang to my mind in support of his contention, and I was not surprised to find that Wright himself had included those same passages in a footnote.
I refer, of course, to Luke 1.1-4...:
...and to John 21.25:
And it would be neglectful not to notice the parallels with Acts 1.1-3...:
...and John 20.30-31:
These passages together cover both halves of early Christian tradition history. Luke assures us that there was no lack of written information about Jesus...:
...John that there was no lack of oral information about Jesus:
Luke, incidentally, does not limit his statement to written materials alone. He asserts that certain things have been delivered to him, and assumes that Theophilus will have been exposed to catechetical material. Nevertheless, it is the ordering of a written narrative that he claims that the many (πολλοι) have undertaken. John, on the other hand, assumes that the many (πολλα) things that Jesus did have not yet been written down.
But, if there were so many sources (both oral and written) from which the evangelists might have had to choose which materials to include and which to exclude, has this plethora of sources left any traces? Do we have evidence of much oral and written early Christian tradition?
Keeping in mind the vicissitudes of history, and that we ought not to expect even a decent percentage of all historical material to have survived the centuries, the answer is yes.
Many sources preserve for us certain floating words or deeds of Jesus, and bear evidence to a rich oral transmission of early tradition. Furthermore, many actual texts have been unearthed in the desert sands of Egypt and other arid regions. We do not always know the exact provenance of each text or tradition, but they are evidence that there was no shortage of people willing and eager to pass on, both in writing and orally, the stories and sayings of Jesus.
Not all such items carry equal merit and authority. It is not my purpose here to either defend or attack the contents of any such traditions.
Furthermore, it is not my intention to state or imply that any or all such traditions predate Luke or John. They are adduced only as support for what Luke and John have to say about written and oral information. The Lucan and Johannine statements stand out all the more in the light of this plurality of tradition, even if all that we have extant turns out to be later than either Luke or John, or both.
These traditions, then, examined in the light of both Luke 1.1-4 and John 21.25, argue eloquently that there was in the primitive church no scarcity of traditions, both in oral and in written form, about Jesus of Nazareth.
It must ever be remembered that these are merely the traditions that we have uncovered. And it is beyond doubt that we have not discovered all that was ever spoken or written about Jesus.