Biographies are narratives but they are narratives without rhythmic structure (like poetry); instead they follow a natural flow of speech with ordinary grammatical structure. This is relevant because the Gospels too are continuous prose narrative.
But so what?
Historical works from the Greco-Roman mediterranean proudly self-identity as relaying witness testimony.
See this page to analyze these 4 supporting arguments:
This is relevant if the Gospels likewise claim to relay testimony.
But so what? Plausibly...
Unlike dramas (for example), biographies in this era tended to be between 10,000 and 25,000 words long. This is relevant because the Gospels are 11-19k words long. (Mark has 11,242 words; Matthew has 18,305; Luke has 19,428; John has 16,150).1
Unlike most other genres (which may focus on things like a time period, large-scale event, or the goings-on of a government, Greco-Roman biographes focused their attention throughout the work on a single character.
Plutarch: “If I do not record all thermos celebrated achievements or describe any of them exhaustively, but merely summarize for the most part what they accomplished, I ask mar readers not ot regard this as a fault. For I am writing biography not history, and the truth is that the most brilliant exploits often tell us nothing of the virtues or vices of the men who performed them, while on the other hand a chance remark or a joke may reveal far more of a man’s character than the mere feat of winning battles in which thousands fall or marshaling great armies, or laying siege to cities.”
- Ben Witherington: “notice how rarely Jesus is not the center of attention of any given narrative. Take, for instance, Mark’s Gospel (an exception would be the story about Herod in chap. 6, but even there Jesus is discussed at 6:14-16). Jesus or his teaching is the subject of over 44 percent of all the verbs in Mark’s Gospel, and in almost any given narrative, Jesus is either the center of attention or discussion, or not far from the spotlight. These books are the p23 good news about Jesus, and they seldom stray any distance or length of time from their main subject.
Unlike other genres, Greco-Roman biographies placed a heavy emphasis on trying to morally capture the virtues and vices and other characterstics of their subject through their choice of which words and deeds to narrate.