What the Bible says about Healing and Forgiveness of Sins
(From Forerunner Commentary)
Jesus sets the spiritual and physical in the right perspective. Since sin was responsible for the man's paralysis, He deals with the cause first, then the effect. All actions are subject to the law of cause and effect; for every action there is a reaction. The man's physical ailment was not nearly as heavy a burden as his spiritual corruption. In reality, physical healing is meaningless without a sound mind. Psalm 103:3 can be seen as a prophecy that the Christ would forgive sins related to sickness and disease.
Martin G. Collins
The Miracles of Jesus Christ: Healing a Paralytic (Part Two)