Realism vs. the Icon

Consider this representation of Jesus from late antiquity / the early middle ages:

                                                     

If you look carefully, the two halves of the face are different. The portrait expresses a theological understanding of Jesus: he is part man, part God. He combines two natures that actually can't be combined. Except for orthodox believers, God combined them by becoming human. (John Hamer lecture)

   The unknown painter was most certainly not trying to represent the historical Jesus in a realistic way. He wasn't painting a portrait of Jesus. 

    The New Testament and the texts that were excluded from the New Testament but were considered scripture by groups of Christians deemed heretical by the bishops likewise were composed and collected decades after Jesus had lived. No doubt some sayings and parables of the historical Jesus survive in these texts. Perhaps also some history - the crucifixion, for example. But these texts are also much more a literary icon of Jesus making theological points, points that were at the center of worship for the different congregations and eventually for the dominant Catholic-Orthodox Church. It is as confusing, I think, following the John Hamer lecture, to read them naively as history as it is to see the icon painting of Jesus as a portrait.  Icons let in a light from another world to illuminate the physical things in this world, at their best. 

  This is also a good analogy to metaphysical beliefs (e.g. the world is Creation, or the world is cold, black, indifferent space and matter doomed to entropy, etc.): such beliefs are the light (or shadow) in which the physical things of the world (including ourselves) appear.