Stage 1: Traditions from the Ministry of Jesus (Traditions stemming from the historical ministry of Jesus in the late 20s CE)What interests me here is not Skinner's critique of Pitre's monograph. I haven't yet had a chance to said monograph, so I cannot speak one way or another to whether the review is fair. What does interest me is the history of this three-stage model. Skinner associates this with form criticism, and rightly so: the stage-model received a very clear articulation under the classic form critics. What I would like to observe here is that they are not limited to the form-critical model of gospel origins.
Stage 2: Post-Resurrection Preaching of the Disciples (Religious convictions about Jesus that arose after his death)
Stage 3: The Writing of the Gospels by the Four Evangelists (Texts and traditions about Jesus that developed during the writing of the gospel narratives; what is often referred to as the evangelist’s Sitz im Leben)
In point of fact, you can see exactly the same three stages supposed in the work of Birger Gerhardsson, who was hardly a classic form critic, and more recently in Bauckham, who is an inveterate critic of classical form criticism. In my own soon-to-be-published monograph, which is as skeptical of form criticism as anything written by Gerhardsson and Bauckham, I suppose something much like these three stages as a structural, organizing, principle of the latter half of the book, describing them (respectively) as the dominical, the ecclesiastical, and the evangelical settings. Indeed, it is difficult to imagine how you could think about the origins of the canonical gospels without something like this basic outline.
But this basic outline will admit of significant variation, precisely because it is so basic. The most obvious variations will have to do with the substance of each stage, which will vary from model to model. Bultmann and Gerhardsson do not vary because one has the second stage and the other does not. They vary because in filling out the substance of that stage Bultmann turned to 20th-century Yugoslavian folk singers, while Gerhardsson turned to contemporaneous Pauline and 4th-century rabbinic texts (yet somehow Gerhardsson is the one dinged for anachronism). Incidentally, we probably would want to quibble with privileging "preaching" in the second stage. Yes, preaching was important, but the extensive evidence of early Christian scriptural exegesis in the gospels suggests that there was also a lot more intellectual work going on then just preaching. Gerhardsson brings out this dimension much better than Bultmann.
There is a less obvious variation on these stages however, namely to do with how the stages interact. Gerhardsson is much more conscious than, say, Bultmann that they are heuristically-sequential rather than temporally-sequential phases. For instance, he allows more fully for the possibility that all three stages could have begun during Jesus' lifetime. Not only was Jesus teaching during his ministry, but his followers were drawing religious convictions about him and thus beginning the memorial processes that led to the composition of the gospels (and he allows for the possibility that writing, in the form of notes based upon Jesus' teaching, were being generated already during his ministry; I don't know if we can show this to have been the case, but I also don't know if we can show that it wasn't. Incidentally, Gerhardsson's narrative helps us see why it is perhaps not quite adequate to restrict the development of religious convictions about Jesus to the post-resurrection period: such convictions were modified after Easter, no doubt, and perhaps extensively, but they began earlier). Ultimately, "stages" might not be the best term. It would seem to suggest a strict temporal succession between the three that is perhaps not warranted by the data. Indeed, even on form-critical terms alone, the preaching did not end when the writing began. The stage-model has much truth to it, and in its basic insights probably indispensable, but like many heuristics tends to be somewhat aseptic.