What do we know about Jesus? Here is what Karen Armstrong says in “A History of God”:
"We know very little about Jesus. The first full-length account of his life was St. Mark’s Gospel, which was not written until about the year 70, some forty years after his death. By that time, historical facts had been overlaid with mythical elements, which expressed the meaning Jesus had acquired for his followers. It is this meaning that St. Mark primarily conveys rather than a reliable straightforward portrayal.
Mark’s Gospel, which as the earliest is usually regarded as the most reliable, presents Jesus as a perfectly normal man, with a family that included brothers and sisters. No angels announced his birth or sang over his crib. He had not been marked out during his infancy or adolescence as remarkable in any way.
There has been much speculation about the exact nature of Jesus’ mission. Very few of his actual words seem to have been recorded in the Gospels, and much of their material has been affected by later developments in the churches that were founded by St. Paul after his death.
In St. Matthew’s Gospel, Jesus is made to utter violent and rather unedifying diatribes against “the Scribes and Pharisees,” presenting them as worthless hypocrites. Apart from this being a libelous distortion of the facts and a flagrant breach of the charity that was supposed to characterize his mission, the bitter denunciation of the Pharisees is almost certainly inauthentic.
Luke, for example, gives the Pharisees a fairly good press in both his Gospel and the Acts of the Apostles, and Paul would scarcely have flaunted his Pharisaic background if the Pharisees really had been the sworn enemies of Jesus who had hounded him to death.
The anti-Semitic tenor of Matthew’s Gospel reflects the tension between Jews and Christians during the 80s. The Gospels often show Jesus arguing with the Pharisees, but the discussion is either amicable or may reflect a disagreement with the more rigorous school of Shammai.
After his death, his followers decided that Jesus had been divine. This did not happen immediately; the doctrine that Jesus had been God in human form was not finalized until fourth century. The development of Christian belief in the Incarnation was gradual, complex process. Jesus himself certainly never claimed to be God."