It is standard Christian theology: We see the fullest expression of God’s character in Jesus. That includes Jesus’ life before the cross, in the experience of the cross, and after the cross. The epitome of information about God that humanity has ever had is Jesus. Although believed (although not necessarily always categorically affirmed) by millions of Christians, let’s not forget the obvious.
First, all the knowledge had about God in the pre-Jesus era, and that was considerable, was still partial. At the same time, those pre-Jesus folk did not normally understand how partial their knowledge was. When that situation is brought into the life of the Jewish nation of Jesus’ time, we can only imagine what it would have taken for Jesus’ countrymen to accept Jesus as the full expression of God.
How easily would any of Jesus’ contemporaries have readily accepted that the Jewish experience of the past fell short of what Jesus presented about God? Would it not have been almost impossible for Jesus’ contemporaries to either see Jesus as the counter position to what most Jews thought about God, or even to see Jesus as the fulfillment of all they understood Judaism to be saying about God?
Second, when Jesus is not taken to be the fullest expression of God that humanity has ever experienced, such rejection requires some kind of reason or explanation. Over the centuries numerous reasons have been floated – that the incarnation of God is an intellectual absurdity, that the Jesus described in the Gospels is a literary work of a community looking for authentification, that the moral teaching of Jesus reflects an abandonment of justice, that spiritual regeneration of a human soul is psychologically impossible – these are only some of the reasons proposed to justify why Jesus could not have been the fullest expression of God to appear to humanity.
Interestingly, these folk just described don’t think that the NT portrayal of Jesus is correct to the facts. Furthermore, these folk do not think their view of Jesus is incorrect.
I think it is only fair to the spirit of inquiry to take the issue one step further. Could there be some thinking (either conscious or unconscious) that a rejection of the New Testament view of Jesus justifies not having to deal with Jesus God, and that is exactly what they want? That they don’t want to deal with Jesus as God for the obvious reason that it would put some claim on their lives, a claim under which they do not want to live? Could it be that there is some degree of intellectual dishonesty involved?