Jesus uses an interesting phrase in today's gospel which is the story of the healing of the crippled man. His friends can't get him in through the door so they put him down through the roof.
When Jesus tells the men that his sins are forgiven the Pharisees object that only God can forgive sin. Then Jesus uses the phrase "but to prove to you that the son of man has authority to forgive sins...."
Jesus performs the miracle specifically to prove that he is the Son of God. How many small miracles does Jesus work in our lives, a spiritual insight which solves problems, a moment of grace that enlivens us, a coincidence that is unexplainable. He does hundreds of these in our life whenever we need them and still we don't see.
Have we tried to develop the habit of seeing with the eyes of faith? When we attempt this habit and develop it, we begin to see the obvious hand of God at work everywhere. And we realize that healing a cripple is not such a big deal for a God who has the whole world under his control!