Rom 7:7; Rom 3:20; 3:19; Gal 3:21-23; Rom 2:1; John 8:7-9
(Rom 7:7) What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet.
(Rom 3:20) Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
(Rom 3:19) Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God.
From these verses and others it’s pretty clear that the function of the law is to cause us to realize our guilt before God by exposing sin that is already in us.
Some people think that the law is an instruction list of “what to do”. However, this is not its primary function. The law functions to expose us for what we are. When the law comes, we are already condemned.
The purpose of the law is to bring our guilt to our conscience. It is a witness against us (Deut 31:26) Jesus proved this in the sermon on the mount, by expounding on the law in a more thorough way. The law taught not to commit adultery, but Jesus said that if we look on a woman with lust we have already commited adultery in our heart. The Law says not to kill, but Jesus said that if we have an angry thought toward our brother, or call someone a fool, we are guilty.
This shows us that the law is not just concerned with what we do in our actions, or even what we intend to do. The law exposes the true condition of our heart and judges us based on what spontaneously comes out of our sinful nature (the flesh).
The problem with the Pharisees in the Gospels is that they thought they could cleanse the “outside of the cup” (using the law to focus merely on their behavior) without realizing the corruption that was on the “inside of the cup” (letting the law pierce to the thoughts and intentions of the heart) (Matthew 23:26).
Therefore they thought that if they kept themselves from “sinful outward behaviors” it was enough to be justified before the law’s eyes, not realizing that the law actually condemned what they were, not just what they did.
Jesus’ goal in the sermon on the mount was to show that it was the desires that sprang from the heart that God was judging, not merely the outward actions that could be seen by men. God looks at the heart, and in the light of God’s law, we are all guilty. Once again, this is why Jesus told the Pharisees to cleanse the “inside of the cup” and then the outside will be cleansed also.
Paul also focused on the law in the same way in Romans 7, where he said that the commandment “thou shalt not Covet” really brought him to his knees. That command means “don’t even have the desire in the first place.”
The law demands holiness at the core of our being, at the root of our desires, not just an outward performance. Anyone who honestly lets the law do this work of exposing will see that he is ruined. Self deception exists when we think that somehow the law is only recommending certain behavior to us.
The law was given to show guilt, and in that sense it is a “schoolmaster” to lead us to see our need for Christ. (gal 3:24) It’s purpose is to bring us to a place where we agree with God’s judgement on ADAM, the fallen human race and to where we agree that Christ must be manifested in our lives. It is to eventually exhaust us so that we will no longer have any hope in ourselves and will turn our attention off ourselves and onto Christ!
We go from merely viewing the cross as the instrument that God used to forgive us of our sins, to seeing that it is also the instrument for God to deliver us from all the self effort.
The law shows us our need for such a deliverance and brings us to a place where we are prepared to hear that we have been crucified with Christ, so that Christ can now live in us.
As Paul said in Galatians 2:20, “I have been crucified with Christ – nevertheless I live, yet not I but Christ in me. And the life I now live in the flesh I live in faith of the Son of God who loved me and gave Himself for me.”
The law transfers the object of hope and faith from ourselves to Christ by bringing us to a place of awareness of the fallenness and absolute hopelessness of the old creation and prepares our hearts to put our hope fully in the Gospel of Christ.