Why is the law of the Lord perfect in converting the soul?

Psalm 19:7 "The law of the Lord is perfect in converting the soul."

Psalm 19 gives us some insight into why God's law is used to revive someone's life. The law (the Ten Commandments) makes those who are simple to become wise--it enlightens one's eyes to fear the Lord! God's commandments are true, right, and enduring. The law is used to discern the error of our ways as the psalmist explains. The apostle Paul put it this way in Romans 7:7: "Yet if it had not been for the law, I would not have known sin. For I would not have known what it is to covet if the law had not said, "You shall not covet." As a result, the law stops a sinners mouth from justifying himself before God. Romans 3:19-20 informs us that the law stops our mouths from justifying ourselves, leaves us helpless and guilty before a holy God, brings the knowledge of sin by defining it for us, and points us to the Savior! "Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin."

I love what Charles Spurgeon said concerning the Ten Commandments in regards to the use of the law in evangelism:

"But more, there is war between thee and God's Law. The Ten Commandments are against thee. The first comes forward and says, "Let him be cursed, for he denies Me. He has another god besides Me, his god is his belly, he yieldeth homage to his lust." All the Ten Commandments, like ten great cannons, are pointed at thee today, for you have broken all God's statutes, and lived in daily neglect of all His commands. Soul! thou wilt find it a hard thing to go to war with the Law . . .What will ye do when the Law comes in terror, when the trumpet of the archangel shall tear you from your grave, when the eyes of God shall burn their way into your guilty soul, when the great books shall be opened, and all your sin and shame shall be punished?"

God's law has its appropriate place. It's not used as a moral ladder to climb yourself into heaven. It can't be done! You will never be good enough to earn or merit forgiveness from God--no matter how hard you try--your efforts are futile and an insult to God's holiness. Picture yourself in an earthly courtroom, all the evidence is laid out--you are guilty! You have been sentenced with a $100,000 fine or time in prison. You don't have the money, so you are handcuffed and led off to jail. All of a sudden, the Judge speaks up, "Hold that young man there!" The Judge steps down from his judgment seat and walks over to you and pulls out a checkbook and writes in a $100,000. He says to you, "I've just paid your fine, you are free to go!" You see, that makes sense in light of the fact that you broke the law and that there was a consequence to it.

If we go around telling people that they need Jesus without taking the time to show them why they need Jesus, that they have offended God by breaking his law, they will not come to Jesus with the right motives. They will come seeking an improved life of health, wealth, happiness, and an easy life. But the Bible promises persecutions, trials, and temptations--and peace in Jesus, knowing that you're saved from God's wrath. You see, the law makes us realize that God's wrath against our sin is just, and that we actually do deserve to be punished in hell for eternity. This bad news about the law makes the good news of Jesus make sense! He paid our fine!

In closing, hear the words of Dr. Martin Loyd-Jones:

"A gospel which merely says, 'Come to Jesus,' and offers Him as a friend, and offers a marvelous new life, without convincing of sin, is not New Testament evangelism. (The essence of evangelism is to start by preaching the Law; and it is because the Law has not been preached that we have had so much superficial evangelism.) True evangelism... must always start by preaching the law."