The purpose of the Law is to reveal sin. That this is the purpose of the Law can be seen from the account of the giving of the Law as reported in the nineteenth and twentieth chapters of Exodus. Moses brought the people out of their tents to have God speak to them personally from a cloud. But the people trembled with fear, fled, and standing aloof they begged Moses: "Speak thou with us, and we will hear: but let not God speak with us, lest we die." The proper office of the Law is to lead us out of our tents, in other words, out of the security of our self-trust, into the presence of God, that we may perceive His anger at our sinfulness.
All who say that faith alone in Christ does not justify a person, convert Christ into a minister of sin, a teacher of the Law, and a cruel tyrant who requires the impossible. All merit-seekers take Christ for a new lawgiver.
In conclusion, if the Law is the minister of sin, it is at the same time the minister of wrath and death. As the Law reveals sin it fills a person with the fear of death and condemnation. Eventually the conscience wakes up to the fact that God is angry. If God is angry with you, He will destroy and condemn you forever. Unable to stand the thought of the wrath and judgment of God, many a person commits suicide.
VERSE 17. God forbid.
Christ is not the minister of sin, but the Dispenser of righteousness and the Giver of life. Christ is Lord over law, sin and death. All who believe in Him are delivered from law, sin and death.
The Law drives us away from God, but Christ reconciles God unto us, for "He is the Lamb of God, that taketh away the sins of the world." Now if the sin of the world is taken away, it is taken away from me. If sin is taken away, the wrath of God and His condemnation are also taken away. Let us practice this blessed conviction.
VERSE 18. For if I build again the things which I destroyed, I make myself a transgressor.
"I have not preached to the end that I build again the things which I destroyed. If I should do so, I would not only be laboring in vain, but I would make myself guilty of a great wrong. By the ministry of the Gospel I have destroyed sin, heaviness of heart, wrath, and death. I have abolished the Law, so that it should not bother your conscience any more. Should I now once again establish the Law, and set up the rule of Moses? This is exactly what I should be doing, if I would urge circumcision and the performance of the Law as necessary unto salvation. Instead of righteousness and life, I would restore sin and death."
By the grace of God we know that we are justified through faith in Christ alone. We do not mingle law and grace, faith and works. We keep them far apart. Let every true Christian mark the distinction between law and grace, and mark it well.
We must not drag good works into the article of justification as the monks do who maintain that not only good works, but also the punishment which evildoers suffer for their wicked deeds, deserve everlasting life. When a criminal is brought to the place of execution, the monks try to comfort him in this manner: "You want to die willingly and patiently, and then you will merit remission of your sins and eternal life." What cruelty is this, that a wretched thief, murderer, robber should be so miserably misguided in his extreme distress, that at the very point of death he should be denied the sweet promises of Christ, and directed to hope for pardon of his sins in the willingness and patience with which he is about to suffer death for his crimes? The monks are showing him the paved way to hell.