The scribes asserted that only God could forgive sins, yet Jesus not only forgave sins, but showed that he had also another power that belongs to God alone: the power to disclose the secrets of the heart. They, of course, did not reveal what they were thinking.
Scripture says that some of the scribes said within themselves: “This man is talking blasphemy.” And Jesus, aware of their thoughts, said: “Why do you think evil in your hearts?”
Now only God knows the secrets of the heart.
As the prophet says: “You alone know the heart” and “God searches the mind and the heart.” And so, to prove his divinity and his equality with the Father, Jesus brought their secret thoughts into the open, which they had not dared to do for fear of the crowds.
In doing this, he showed his great compassion. “Why do you think evil in your hearts?” he said. After all, if anyone had reason for complaint it was the invalid. As though cheated he might well have asked: “Have you come to heal something else then? To put right a different malady? How can I be sure that my sins are forgiven?” In fact, however, he said nothing of the sort, but surrendered himself to the healer’s power.
The scribes, on the other hand, feeling left out and envious, plotted against the good of others. Jesus therefore rebuked them, but with forbearance. He said: “If you do not believe the first proof, and regard it as an empty boast, then see, I offer you another by revealing your secret thoughts; and to this I will add a third.” What is the third to be? The healing of the paralytic.
Jesus did not give a clear manifestation of his power when he first spoke to the paralytic. He did not say: “I forgive you your sins,” but: “Your sins are forgiven.” When the scribes forced him, however, he showed his power more clearly, that you may know, he said, that the Son of man has power on earth to forgive sins.
Before doing this Jesus asked the scribes: Which is easier to say, “Your sins are forgiven,” or to say, “Pickup your mat and go home?” This was the same as asking: “Which seems easier to you, to heal the body, or to forgive the soul its sins?
Obviously, it is easier to heal the body.
Indeed, as far as the soul is above the body, so far does the forgiveness of sins surpass physical healing. However, since the one is invisible, but the other visible, I grant you as well this lesser, visible miracle as proof of the one which is greater but invisible.”
Thus he showed by his deeds the truth of what John had said of him: that he takes away the sins of the world.
St John Chrysostom