Logic is a powerful tool, but tools can destroy as well as build. Used wrongly a tool can be deadly to the user. The Pharisee’s logic here is valid. They think Jesus is blaspheming. In Mark they are recorded as thinking, “Who can forgive sins but God alone?” They are right. God is always the most offended party in our sin, it is ultimately His prerogative to forgive sin. Your sin never hates anyone as much as it hates God. Sin mocks and belittles all that God is. Think of an attribute of God, then meditate a little, it shouldn’t take long to see how even the smallest sin laughs at that attribute. “Your omnipotent God, do something about this! You are all wise; well I think this is the better way to live. All seeing, do you see this? Your gracious, you’ll forgive this sin.” Sin is the hating of God, the seeking to de-god God. So the Pharisees rightly reason thus:
Only God can forgive sin.
Jesus is a man.
Therefore Jesus cannot forgive sin.
The logic is valid; the problem is that the second premise is false. Jesus is more than a man. That’s the point of this text, the healing of this paralytic is a subplot. Jesus is the God-man with authority to deal with all of our problems at the root. Jesus doesn’t come as the Great Physician to merely alleviate symptoms, but to do radical surgery by His own wounds.
All sickness is due to sin. It may or may not be due to a particular sin in your life, but all sickness is ultimately due to sin, namely the sin of Adam. Sickness then is a vivid, pervasive picture of the heinousness of a greater plague of which we all suffer, sin. The greatest disease is not to be dreaded as much as the least sin.
Jesus comes to make all things new; a new heaven and a new earth with no more sickness, pain, or death. In order to do this He will have to deal decisively with sin. This He did on the cross, as the God-man. As Anslem would reason, only God can deal with sin, only man ought to, and only in Jesus do the can and ought meet.
So it is the Pharisees, not Jesus, who blasphemed that day. I do not rejoice that the Pharisees blasphemed, but I do rejoice that it was blasphemy. Jesus does have the authority to forgive sin.