The Gospels belong to the genre of Greco-Roman biography, particularly those of the Early Roman Empire (which might be considered a sub-genre). These are information-based biographies, and best match works like Suetonius’ Lives of the Caesars.
• Ancient bios and letters predominated.
• Gospels internally match ancient bios.
• Gospels are honest historical accounts of Jesus’ life.
• Gospel authors strove to relay only witness testimony.
• Gospel Jesus-bio content is early/sourced.
The Gospels consistently relay material they received in writing their reports; it came from sources rather than originating with them.
• Gospels spew provably early stories (e.g. AD 30-40).
• Gospels claim to be non-fiction (non-myth).
• E.g. Gospel Jesus-bio was passed down orally.
• 1st church's Jesus-bio is a subset of witness testimony.
• The Gospels are honest
• The Gospels got witness-approval or close on Jesus-bio.
• In general, Christians relayed Jesus-bio (rather than creating it).
• Examples of used witnesses abound (E.g. we have clear examples from each gospel, and we can ostensibly identify sources, like Peter, Mary, Salome, Lk 1's teachers.
• Examples of written sources used abound (E.g. Q, the pre-Markan Passion narrative etc.)
• Craig Keener: “In this respect, the Gospels resemble biographies of Plutarch, who emphasized themes in his sources still relevant for his own day but rarely imposed his own era’s issues into sources that lacked them.” [Christobiography (Eerdman's 2019), 329.]
The Gospel authors put in serious effort to learn and then pass down in their gospels all and only true Jesus-biography.
• The Gospels claimed to investigate (e.g. in Lk 1:1).
• The Gospel authors travelled to gather info.
• Historians critically examined claims/sources.
• Gospels strove to relay only witness-based testimony.
Whether or not the Gospel stories originated before the Gospels themselves were, when they did form, they were formed in honesty; they are not fabrications.
• The Gospels lack time-place absurdities.
• The Gospels spew confirmed non-legendary content.
• Christian Jesus-bio was honest.