The gospels belong to the ancient genre of biography.  These ancient biographies were concerned with providing examples for readers to emulate, while preserving and promoting the subject’s reputation and memory.  Thus, they were about kerygma or preaching.  They were not biographies in the modern sense.  The biographies of Jesus are more like apocalyptic history, depicting Jesus as caught up in events near the end of time.  Despite this, scholars are confident that the gospels do provide a good idea of the public career of Jesus.  There is no guarantee that the gospels are precisely historical in our modern sense of history.  These are faith documents, not eyewitness accounts.  Modern scholars are cautious of relying on the gospels uncritically, but nevertheless they do provide a good idea of the public life of Jesus.