Jesus' authority to heal the body testifies to his authority to forgive (9:6-7; compare 9:12). Jesus' authority (vv. 6, 8) is a central focus of the context (7:29; 8:9, 27; compare 28:18). This narrative teaches us a number of lessons.
Jesus Is Moved by Our Faith, Even on Behalf of Others (9:1-2)
The paralytic was not alone in his faith; his friends who brought him believed too. Thus this account teaches us about intercession: we may pray for others, not merely for ourselves. Mark's fuller narrative recounts the character of the friends' faith: they were so persistent and determined to reach Jesus, so confident that their friend would be healed if they reached him, that they dug through the roof (Mk 2:4). Faith is not simply working up a feeling or suppressing doubts, but demonstrated commitment to getting to the One on whose power we stake our trust.
We Need Forgiveness Even More Than Physical Healing (9:2)
Out of his care for us, Jesus places first things first (as in Ps 119:67, 71, 75). Although Jesus' miracles teach us about his power to heal physically, these signs are meant to turn our attention to the kingdom of God (Mt 6:33; 9:12). Thus in Acts signs and wonders constitute the primary method of drawing attention to the claims of the gospel, but it is the gospel itself that is paramount (as in Acts 14:3). In this narrative, physical healing certainly earns the crowd's attention (Mt 9:8), as miracles usually did (for example, 8:27, 34; 9:26, 31, 33).
Speaking for God Usually Invites Opposition (9:3-4)
Jesus' unique authority on earth to forgive sins sets him apart from other people, a claim that disturbed the teachers of the law (v. 3), who wrongly supposed that speaking for God was their own role. Others might pronounce sins forgiven once clear atonement was made, but no atonement was made here (compare E. Sanders 1990:62-63). Thus the theologians decided that Jesus was blaspheming, which in the general sense simply meant "reviling" (in this case, God). Before Jesus is done, however, he will announce that God delegated to him the authority to forgive sins in general (v. 6; compare Dan 7:13)!
Jesus' Authority to Heal Demonstrates His Authority to Forgive (9:5-7)
Because healing as opposed to forgiveness is empirically verifiable, the teachers of the law would conclude that it is easier to say "Your sins are forgiven" (Meier 1980:91). By performing a sign that is empirically verifiable, however, Jesus argues that he is God's authorized agent and therefore has authority . . . to forgive sins. The reasoning runs something like a traditional Jewish qal wahomer ("how much more") argument: if God would authorize Jesus to visibly heal the effects of humanity's fallenness, would he not send him to combat that fallenness itself?
Although physical healing is secondary to forgiveness, such healing is often crucial not only for compassionately meeting some of our most pressing human needs (9:36) and empowering us for greater service to the Lord (20:34) but also for drawing attention to Jesus' power to do other works. People who reason today that Jesus can heal either physically or spiritually but not both are like the radical critics who debate whether Jesus was a wisdom teacher or a prophet, a messiah or a healer. The question is forced-choice logic; why can he not be both, as the text teaches us? Without guaranteeing that God always chooses to perform miracles we might desire, I have personally witnessed how nonbelievers healed in answer to prayer sometimes end up committing their lives to the Lord Jesus.
Jesus' Signs of Authority Bring God Glory (9:8)
Often God will vindicate his work despite opposition if we persevere in doing good (compare 7:28; 8:27; 9:33; 12:23). When God provides clear testimony of his power, expect hostility from those who resist God's testimony; but recognize that God's works will always bring him more glory in the end.