“Whether is it easier to say to the sick of the palsy, Thy sins be forgiven thee; or to say, Arise, and take up thy bed, and walk?”
Which is easier: to say to this paralyzed man, your sins are forgiven, or to say, get up, take your mat and walk? — the question is deliberately provocative because the answer is not what it first appears. Saying your sins are forgiven is actually easier in one sense: it is unverifiable. No one can look at a person and see whether their sins are forgiven; the claim requires no visible demonstration. Saying get up and walk is harder in that it is immediately falsifiable — the person either gets up or they don't. Jesus is using the verifiable as evidence for the unverifiable: if the healing happens, it confirms the authority to forgive.
Church Fathers on Mark 2:9
Because the compassion of God deserts not even carnal persons, He accords to them the grace of His presence, by which even they may be made spiritual. After the desert, the Lord returns into the city.
But Matthew writes this miracle as if it were done in the city of the Lord, whilst Mark places it in Capernaum, which would be more difficult of solution, if Matthew had also named Nazareth. But seeing that Galilee itself might be called the city of the Lord, who can doubt but that the Lord did these things in His own city, since He did them in Capernaum, a city of Galilee; particularly as Capernaum was of such importance in Galilee as to be called its metropolis?
He saw the faith of the sick man himself, since he would not have allowed himself to be carried, unless he’d had faith to be healed.