TWH: Richard A. Burridge points out the importance of why we even ask the question about "genre":
"If we were to treat a cartoon featuring Churchill as though it were a photograph, we would soon make mistakes in its interpretation. Similarly, one does not listen to a fairy story in exactly the same way as to a news broadcast. Correct interpretation of a painting or a story depends on a correct identification of what kind of communication it is, that is, of its genre. We differentiate between painting, drama and word, between the spoken word and the written word, between fiction and non-fiction, poetry and prose, tragedy and comedy, legend and history, and so on. . . . Genre forms a kind of 'contract' or agreement, often unspoken or unwritten, or even unconscious, between an author and a reader, by which the author sets out to write according to a whole set of expectations and conventions, and we agree to read or to interpret the work using the same conventions, giving us an initial idea of what we might expect to find." (Four Gospels, One Jesus? A Symbolic Reading, 3rd ed. [Grand Rapids: William B. Eerdmans, 2014], 5)Understanding what type of literature we are dealing with matters. It impacts how we look at a text. There's no question about that. It's interesting how Burridge says genre forms a sort of "contract" between the author/speaker and the reader/listener, and sometimes that is ucconscious. Generally speaking we don't sit down and think about what type of genre something is before we engage it. It happens so quickly, and we are so accustomed to identifying and processing that information that it is natural, without us even knowing that we've done it. It's like breathing or speaking one's native language. Under normal circumstances, no one tries to do it, it just happens. If a person goes to a movie without any prior knowledge about what the content is going to be, that person's brain will begin to process that movie. It just happens.
Genre impacts the way we think about content. It doesn't put a person in a straight jacket per se, but it definitely puts people inside a contained area, free to move about but not a hermeneutical free for all. A certain set of parameters are drawn around the audience that controls/influences how they think about things like emphasis and focus, historicity and accuracy, characters (primary, secondary, etc.; active and passive, structure and parts of a discourse, and all the other elements of discourse.
The last thing that we want to do is do what people did for years (still today, but not as common) when they treated Greek as a "Holy Ghost" language. The last thing we want to do with the Gospels is treat them as some sort of "Holy Ghost" literature, as if someone in the first century might have picked up Matthew and said, "What is this new genre? What is this new type of literature that I have in my hands? God has delivered it down to us like manna from heaven. We can taste and enjoy, but of this world it is not." Granted genres do get come into existence. Something definitely happened with science fiction, for example, after the Enlightenment. And we can connect the development of science fiction to significant advances in science. Creativity expanded as humans made advances in science and technology. The Gospels are different than most literature before it. I say most because in one sense they are not different than what the Jewish people referred to as "the Law, the Writings, and the Prophets." These, like the Gospels, were inspired by God (2 Tim. 3:16-17). But the Gospels are quite distinct, though they share many similarities with Psalm 22, a passion psalm, and the so-called Servant Songs of Isaiah, which describe in great detail and from two different vantage points what would take place to the Son of God on the cross. Still, the Gospels are distinct. They focus on this Son of God, particularly on his death, and they use their long, rich "introductions" to demonstrate that Jesus is the long-awaited Messiah and Lamb of God. The significance of Jesus' death is tied to his identity. Developing that identity is one of the main thrusts of the material leading up to the larger sections of the Gospels that focus on his death.
Burridge's book What Are the Gospels? is one of the most comprehensive analyses on the subject of Gospels and genre. As far as I know he was the first to point out, though I'm sure he wasn't the first to really think such a thing, that no genre is in and of itself unique since all genres have a sort of genre genealogy. He also pointed out that the Gospels needed to be compared to first-century βίοι (biographies). A βίος (biography) is really just a type of γραφή (writing). But calling something a biography is not really the lowest-common denominator in terms of analyzing discourse. What type of βίος is it? Even in the first century, people identified a biography using this term. They did not, so far as I can tell, narrow this down to any sort of sub-category (e.g., popular biography, historical biography, literary biography, reference biography, fictional biography, political biography, philosophical biography, living biography etc.). The sub-categories arise later in modern studies as researchers began to analyze discourse in closer detail.
Here are just a few comments regarding the Gospels as we think about genre:
1. What we find in the Gospels does fall under the category of βίος. Absolutely. Arnaldo Momigliano defines a biography as "an account of the life of a man from birth to death," admitting such a definition is not a very profound one (The Development of Greek Biography [Cambridge: Harvard University Press, 1993], 11). But that's what a biography is. It doesn't have to be profound (I appreciate people that define simple concepts in simple words, even when they could have waxed eloquent!). And definitions like that provide the wiggle room that's needed for further analysis. Now this doesn't mean that a Gospel bears all the characteristics of every single Greek biography. Similarities among biographies, yes; uniformity, no. And if a characteristic is found in some biographies, it does not necessarily mean that the same characteristics are present in the Gospels. For example, just because a contemporary biographer rearranges historical data inside a narrative does not necessarily mean that Luke did. We can generally apply principles for reading and interpreting contemporary biographies to the interpretation of the canonical Gospels. And the divine inspiration of the Gospels has implications on the text. For example, the Gospels are true and accurate accounts, a feature guaranteed by divine supervision. Other biographies were susceptible to tendencies to manipulate and persuade, but the Gospels have as their origin one whose very character is truth.
2. We need to remember the distinctions that exist even among the Gospels themselves. This includes historical distinctions. For example, Matthew wrote first, not Mark. Mark comprises the messages Peter preached in Rome. Luke is writing to an individual named Theophilus to give him an account of Jesus' ministry (particularly his death) and how Jesus' disciples reached the world with the message of the cross in the years that followed.
3. The emphasis in the canonical Gospels is placed on Jesus' death and resurrection. The Synoptics spend about forty percent of their content on the last week of Jesus' life. John spends about that much on the last 24 hours of Jesus' life. This is critical for how we understand the Gospels. This point has greater implications for how we approach the Gospels than whether or not we identify one as belonging to a unique genre.
4. A unique narrative does not constitute a unique genre. Every discourse is unique in some sense. If the "uniqueness" or distinguishing features of a discourse constituted a unique genre then there would be an endless number of genres.
5. There is a tendency among Christians to view the Gospels as unique to the extent that they constitute a new genre. I suppose in part or for some this could be because Christians worship Jesus, the main character of the Gospels. He is so important that anything that tells about him must be unique and highly esteemed as well. To do anything less would be a reflection of what that person thinks about the object of their worship. I think the concept of divine inspiration as well as the content plays a role in this tendency as well. The same thing takes place with the letters of the New Testament. For some Christians, many perhaps most, the letters of Paul are not letters . . . they are epistles. They are some sort of special class of letters. But really Paul's letters are not so different than other letters written in the first century. What makes them distinct to other letters is their content.