On a first reading of the gospels of Matthew, Mark and Luke, it is tempting to take these stories at face value: here are ancient texts that tell us what Jesus said and did. Their reliability and facticity is assumed without question. And this reading of the gospels has been ubiquitous in the Christian churches for much of the last 2000 years.
Today, however, such a reading of the gospels is no longer possible. To start with the most obvious observation: there are four gospels, and each has a different picture of Jesus and his teaching. The fourth gospel, that of St John, presents the reader with a substantially different account of the teaching of Jesus, a conflicting chronology of his life (for example the date of Jesus’ crucifixion) and perhaps most significantly, presents a christology that is radically different from the synoptics. Thus NT scholars have long concluded that the gospels tell us as much about the views of their authors as they do about the events they allegedly describe.
As Christopher Tuckett (Professor of New Testament Studies in the University of Oxford) in his critically acclaimed work Christology and the New Testament: Jesus and His Earliest Followers Edinburgh University Press 2001) comments:
‘The picture of Jesus in John is in many respects very different from the picture in the other three, so-called ‘synoptic’, Gospels. Furthermore, most would agree that, in general terms, the synoptic picture is more likely to reflect the realities of Jesus‘ own time, and the Johannine account represents an (at times) extensive rewriting of the Jesus tradition by a later Christian profoundly influenced by his own ideas and circumstances. However, it is now recognised that what applies to the Fourth Gospel applies equally to all the Gospel: the synoptic Gospels, quite as much as John, have been influenced by the ideas and the circumstances of their authors. Thus in reading all the Gospels, we have to be aware of the fact that we reading accounts of Jesus‘ life as mediated by later Christians and hence we may learn much, if not more, about the latter as about Jesus himself in studying the Gospel texts.’
pp. 105-106 (emphasis in original)