So many people today, are like the people in the time, when Jesus was on earth.
They can only see him as a prophet, as a wise teacher, as a philosopher, or just another carpenter.
In Mark 6:1-6, we can clearly see, that although Jesus was doing all those miracles, for a few years, in front of thousands of people, there were still people, who could not see him as the Son of God. They saw him only as a man. ‘Is not this the carpenter’ they asked. And yet Jesus said that even if they do not believe what he is saying about himself, they should at least believe on the prove of the miracles themselves, which testified that he is the Son of God.
Jesus even asked them at one point who they think that he is, and only Peter had the real revelation that he is the Messiah, the Son of God. Others thought that he is one of the prophets, or whatever else.
Today, so many people still do not see, that Jesus is God himself, as he said that whoever sees him, sees the Father God.
All that some people see today, is that he is a good moral teacher, and based on that, they miss all the miracles and the supernatural God has for them and their life.
Lack of faith, lack of miracles, and Jesus still marvels today, about their unbelief, in whom he says that he is.