Different Source Theory Implications?

I would love to see a decent book written for (or with) students dealing with source-critical methods and pressupositions. But perhaps even more relevant for NT students (especially those going into some pastoral or teaching capacity) is a resource dealing with possible differences that different source-critical methods entail. I'm usually less interested in theology than source criticism but what is the relationship between the two? What are the implications in terms of different interpretations (in exegsis & theology), different historical implications, and any different pastoral implications? I've seen various claims that different source theories imply such differences, but I have not seen much evidence. Two supposed differences I will comment on here.

One is obvious--history. Rearranging the order of composition will obviously imply a different Church history. But what would it look like? What would be the big differences? The most extreme case I can think of is when somone suggests that one or more of the Gospels were written very early (i.e. during Paul's lifetime c.50s CE) or very late (say during the second century c.120s). But even in such extreme cases I haven't seen how Church history should be re-written because little attempt is made to show how history is affected by even these extreme source-theories. If there are important differences in results--what are they? Perhaps I haven't looked hard enough, but most scholars put the Gospels post-Jewish-Roman war (or Mk during) between the 70s-90s and with these guesses not much seems to change if we swap them around, given that evidence of Church history also resides with Paul's letters.

So much for Church history. The other difference I have noticed commented on is in the field of pastoral implications. William Farmer has argued that there are definite differences between source theories. But he did so from the perspective that his theory was more in line with Christian theology and therefore correct! There seems to be unnecessary fear in this line of argument. Farmer's book, The Gospel of Jesus: The Pastoral Relevance of the Synoptic Problem (Louisville: Westminster/John Knowx Press 1994), argues for the superiority of the Griesbach hypothesis (2GH/Mt-Lk-Mk) because the concept of justification by faith is missing in Mk (and so Mk cannot have predated Mt)! I'm a little put off at how this kind of argument might work and I don't think students will follow the logic either. Here is a link to his argument in an earlier form ("The Import of the Two-Gospel Hypothesis") I quote part of the abstract which says that Farmer

shows that Jesus' parables of grace are absent from Mark and "Q". This would mean that someone other than Jesus was responsible for these parables. Farmer suggests that it is inevitable that this view will be disasterous for the preacher who has used these parables as a basis for his own sermons of salvation.

Here are four more quotes:

Therefore, the first import of the Two-Gospel hypothesis is that it restores to the person in the pew the same Scriptures thatthe clergy have. Everyone is on an equal footing. The clergy do not have some esoteric or elitest advantage of knowing about some unknown document or documents not readily available to the person sitting in the pew. This is a boon to communication.

Secondly, the Two-Gospel hypothesis takes the focus off ofthe question of which Gospel is first. To speak of Matthew as first in time implies to some that Matthew is also first in importance. The Two-Gospel hypothesis avoids the difficulty of suggesting that any one Gospel is more important than any other.

But how do we fare when we, who are in the Wesleyan tradition, stand in the pulpit and face a living congregation of sinnershungry for the Gospel, and we have a two-document understanding of the Scriptures? Let us first look in the Gospel of Mark. Do we find Jesus' parable of the Prodigal Son in Mark? No, it isnot in Mark. Can we find it in "Q"? No, it is not in "Q". This means it is in neither of our two earliest and most reliable sources. Why not? Immediately a question is raised which provides critical grounds for some methodological skepticism.

What difference does it make? I suggest that, for those who wish to preach the Gospel with power and a clear critical conscience, the answer is close athand, no further than the Gospel itself.

I don't really see how his reasoning works (perhaps it only works if people are already told to be afraid of what Farmer seems to have feared), but I plan to track down an article by Kloppenborg which I hope deals with questions of theological implications because I'm sure students will want to know such things. Scot McKnight (in Rethinking the Synoptic Problem) refers to "The Theological Stakes in the Synoptic Problem," in The Four Gospels--1992: Festschrift Frans Neirynck vol 1:93-120. So far it is very difficult for me to track down!