Early Christians would have used this passage in Mark to prove their claims about forgiveness of sins through Jesus. Jesus responds to the act of faith of the four men who went to extraordinary means to bring the paralytic before Him. Jesus addresses the latter: 'Son, your sins are forgiven', indicating that he is now before the Divine Healer, not just a miracle worker. We also learn that we can only be restored to wholeness when sin is removed by forgiveness first.
Radical and total healing is the unconditional love of God made present through the unmerited forgiveness of all our sins in the Sacrament of Reconciliation. Jesus is powerful both in word and deed: his power/authority to forgive sins is confirmed by his power to heal the paralytic.
As there is no empirical test, it is surely easier to say that the man's sins are forgiven than to say that the paralytic should get up and walk, for which there would be an immediate empirical test. The healing function of Jesus is a sign of the validity of Jesus' declaration about forgiveness. Jesus represents God. The crowd is in admiration of Jesus. They recognise the Divine presence, even in the face of those who do not believe.
In this tangible way, Jesus manifests the presence of the kingdom in Himself as He carries out this double action, a two-in-one unique experience that all of us need to go through in our relationship of prayer with our God.
Lord, heal me, make me whole and holy.