How do we know really , who was Jesus , the answer must be found in writings about him , mostly such writings if not exclusively are the Gospels , and the letters of Paul .
What Paul wrote was more interpretational than first-hand knowledge , as he admits himself that he never knew Jesus in the flesh , John's Gospel was even further detached from describing the real Jesus , his life or personality .
So we are left with the other three Gospels , Matthew , Mark and Luke . We know very little about these authors , and about the circumstances surrounding their writings , except the very general traits . The three Gospels are more or less identical , most scholars nowadays believe that Matthew and Luke copied extensively from Mark , this would strongly suggest that the two mentioned authors had no first-hand knowledge of Jesus . Even Mark's knowledge of Jesus personally is marginal and distant at best .
There is not any mention in Mark of the appearance or mannerism , of the daily life and habits of Jesus , a bit strange if the man knew and lived around the very vivid and magical Jesus . He could only have known people of the same epoch who knew Jesus personally .
My guess is that Mark could have been a much younger contemporary , who influenced Matthew and Luke to write their books only a full generation or more later , and John nearly a full century down the line . So the immediate thought that comes to mind would be , how can we be so sure , so adamant in our judgment and considerations , when there is no real first hand information or writings.
Kierkegaard put it this way, "God can lift humans to the level of God , or God has to accept the debasement of becoming human ." According to him " the human mind is affronted ; as Jesus claim, or is made to be Christ/God is odiously offensive to human reason . It is an attack on human reason to expect that God would dream of becoming human , of coming to earth as a carpenter and dying on a cross as a common criminal at the hands of the marginal and insignificant people of his lands ."
The whole very disputed theory of Jesus/God was only imposed by high coercion and use of extensive force some 325 years later at Nicea , and only enforced and adopted after 384 C.E. for theological and political purposes . We all have our minds and intellect , we need to be convinced rationally and not blindly accept leaps of faith . It is alright for all of us to be intellectually interested in rational studies and interpretations of religions , all religions . They still do influence and govern most of our thinking and affairs in these sad and crazy times .
Again and as usual my many thanks for your time .