This is a remarkably clear introduction to New Testament narrative criticism, though dated now (it was published in 1990, not long after the dawn of narrative criticism in New Testament studies).
Narrative criticism, in brief, is the study of New Testament narratives (especially the Gospels) "as Scripture in story form" (p. 85). Starting in about the 1980's some scholars began to apply literary criticism, common in the study of secular texts, to the narratives of the New Testament. This came on the tail end of decades of historical criticisms which, though useful, tended to produce understandings of the Gospels dependent on elaborate speculations. The quest for the historical Jesus made guesses about the historical Jesus; source criticism guessed about sources; form criticism guessed about the early church; redaction criticism guessed about the editor or redactor. Such guesses are relatively important, but they have taken the eyes of scholars off of the finished product of what we have in Scripture (redaction criticism was already a move away from this tendency).
Although narrative criticism is not the biblical criticism of today (unlike the historical criticisms were in their day), it represents a drift of New Testament scholarship toward the text itself. As a Christian, I am grateful for this. I believe the text itself to be inspired by God and profitable, whereas historical speculations are important but uninspired.