Mark 2
Jesus Forgives and Heals a Paralyzed Man
2 A few days later, when Jesus again entered Capernaum, the people heard that he had come home. 2 They gathered in such large numbers that there was no room left, not even outside the door, and he preached the word to them. 3 Some men came, bringing to him a paralyzed man, carried by four of them. 4 Since they could not get him to Jesus because of the crowd, they made an opening in the roof above Jesus by digging through it and then lowered the mat the man was lying on. 5 When Jesus saw their faith, he said to the paralyzed man, “Son, your sins are forgiven.”
6 Now some teachers of the law were sitting there, thinking to themselves, 7 “Why does this fellow talk like that? He’s blaspheming! Who can forgive sins but God alone?”
8 Immediately Jesus knew in his spirit that this was what they were thinking in their hearts, and he said to them, “Why are you thinking these things? 9 Which is easier: to say to this paralyzed man, ‘Your sins are forgiven,’ or to say, ‘Get up, take your mat and walk’? 10 But I want you to know that the Son of Man has authority on earth to forgive sins.” So he said to the man, 11 “I tell you, get up, take your mat and go home.” 12 He got up, took his mat and walked out in full view of them all. This amazed everyone and they praised God, saying, “We have never seen anything like this!”
Indeed, who can but God alone can forgive sins?
So.....by declaring the man's sins are forgiven, Jesus was claiming He is God.
Telling the man to pick up his mat and walk, is, showing them the proof, that He is who He claims He is.
“I am trying to prevent anyone saying the really foolish thing that people often say about Him: “I’m ready to accept Jesus as a great moral teacher, but I don’t accept His claim to be God.” That is the one thing we must not say.
A man who was merely a man and said the sort of things Jesus said would not be a great moral teacher. He would either be a lunatic–on the level with the man who says he is a poached egg–or else he would be the Devil of Hell. You must make your choice. Either this man was, and is, the Son of God: or else a madman or something worse.
You can shut him up for a fool, you can spit at him and kill him as a demon; or you can fall at his feet and call him Lord and God. But let us not come with any patronising nonsense about his being a great human teacher. He has not left that open to us. He did not intend to."
Now it seems to me obvious that He was neither a lunatic nor a fiend: and consequently, however strange or terrifying or unlikely it may seem, I have to accept the view that He was and is God."
(CS Lewis, Mere Christianity)