In The Burial of Jesus James McGrath gives an introduction to the methods of scholars who study the Gospels as sources of historical evidence about Jesus.
Note how, throughout, this method assumes:
- That there is a historical Jesus to talk about;
- That there was an oral tradition that relayed information about this historical Jesus to other audiences;
- That the gospels relied on these traditions, at least in part, for their narratives about Jesus.
As stories were retold in and applied to new contexts, they were often shaped by that process, and sometimes the use to which a saying or story was put in between its first telling and its being written down has left its mark on some of the details. Thus there are different levels to the gospels incorporated in the Synoptic Gospels:
(1) There is the teaching of Jesus
(2) which was retold and passed on orally (and/or in written form) in the church before
(3) being placed in the written form accessible to us by the authors of the Gospels.
We need to keep these different levels in mind if we want to understand the Gospels. Similarly, in every story there are two levels that we may relate to, one or both of which may have influenced the present form of the narrative in important ways:
(1) The historical level, in which Jesus said or did such and such, and
(2) the contextual level, in which the Gospel writer (or someone at an earlier time) applied this tradition about Jesus to needs and situations in his own time and church.
. . . . The historian is interested in getting back behind the text, using the text as a means of gaining access to events that supposedly happened earlier.
. . . . The historical approach digs through and seeks to get behind a text to see what if anything can be determined about actual historical events.
. . . . If one wants to ascertain what we can know about Jesus as a historical figure “beyond reasonable doubt,” then historical study is the only way to accomplish that.
. . . . The aim of all this is to uncover a core of information regarding Jesus that most historians, regardless of background or religious upbringing, should be able to agree is authentic. (pp. 55-58)
When it is said that the historian seeks to get back “behind” the text of the Gospels, what is implied is that the text is itself an attempt (at least in part) to record information derived from traditions that are to be traced back to the historical Jesus.
These assumptions, according to this method, are prerequisites “if we want to understand the Gospels”.
Certainly form criticism can claim to have traced certain Gospel sayings back to “originals”. But this method is not evidence of the hypothesis of oral transmissions, but a conclusion based on its presumption.