Suppose there’s a certain room in a house that is completely covered in dust. A man walks into the room and begins to sweep using an old straw broom. Although it looks like the broom will remove the dust, it actually makes things worse. As the man sweeps, the dust begins to lift off the ground and fill the air. So the man sweeps even harder. But the more he sweeps, the worst things get. Eventually the dust begins to choke the man so he gives up and walks out of the room.
A few hours later, a lady walks into the room and sees that it’s completely covered in dust. Instead of reaching for the old straw broom, she fills a bucket with water and washes the dust away.
Here we find that the room represents a person’s heart. The dust represents their sin. And the old straw broom represents the law.
What looks like it will remove sin actually makes things worse.
The law does not eradicate sin. It simply just reveals what sin is. The Bible says: “I would not have known what sin was had it not been for the law. For I would not have known what coveting really was if the law had not said, ‘You shall not covet'” (Romans 7:7)
In fact, the law doesn’t just reveal sin. The Bible teaches that it actually provokes it: “Sin, seizing the opportunity afforded by the commandment, produced in me every kind of coveting… When the commandment came, sin sprang to life…the very commandment that was intended to bring life actually brought death” (Romans 7:8-10).
Trying to obey the law in an attempt to remove sin is just as futile as trying to sweep away the dust with an old straw broom. The more we try and obey, the more we realize how utterly sinful we truly are. The law doesn’t make us good. It just reveals that we are not good and that we are unable to become good. It reveals our need for a savior.
But then enters the lady with the bucket of water. The bucket represents the gospel.
What could not be done through obedience to the law, is accomplished through the death of Jesus. When a person places their faith in Jesus, all their sin is washed away. They are made clean before a Holy God.
The law is the diagnosis. The gospel is the cure. The purpose of the law is to show us our sin. The purpose of the gospel is to show us our Savior.
(Adapted from an illustration by John Bunyam in his excellent book ‘Pilgrim’s Progress’)