Reflecting Sin: The Pedagogical Use of the Law

"Ouch!" That first look in the mirror every morning doesn’t get any easier, does it? In fact, I’d rather do without looking in mirrors at all. And I might get away with it — for a few days. Because, although I wouldn’t know my hair was looking like a mohawk, that yesterday’s ketchup was still on my chin, or that last night’s basil was lodged between my front teeth, my wife and children would, and so would my employer and colleagues. And that might well have more painful consequences — socially and even financially — than just looking in the mirror. So, although it is humbling, and sometimes horrifying, I still meet up with my mirror every morning. It sends me to my hairbrush, my shaver, my toothbrush, and my soap.

Similarly, although we may not always enjoy reading or hearing God’s law, we must keep reading and preaching it because it reveals His holy standards, highlights our desperate need (which is humbling and horrifying), and sends us to God’s gracious remedy — the gospel of Jesus Christ.

But imagine that you stumbled into my bathroom one day and saw me scrubbing myself with the mirror or brushing my teeth with a small broken piece of it! Apart from shouting, “Stop! Are you mad?” I hope that you would also quickly convince me that while the mirror shows what needs cleaning, it is dangerous to do the cleaning with it. The attempt is doomed to fail, as it would only produce a bigger mess.

Well, that more or less sums up Paul’s ministry to the Galatian believers. They had been in the tortuous confines of Law Prison (Gal. 3:23), trying to earn release with their works of obedience. The law demanded and commanded, demanded and commanded. They tried and failed, tried and failed. But despite the daily futility and failure, they couldn’t—or wouldn’t—dare stop trying.

Then, one day, the apostle Paul came and preached the gospel of a crucified Christ. He preached a Christ who had obeyed the law for sinners, a Christ who had suffered the penalties of a broken law, and a Christ who had abolished the Old Testament rituals and ceremonies by fulfilling them.

Many Galatians believed in Christ. Their chains fell off and they left the bondage of Law Prison behind to enjoy a new world of freedom and liberty. Who would ever give that up?

Tragically, the Galatians did. Under the influence of Judaizing false teachers, they reverted to salvation by the law. Paul wrote with great urgency to remind them of how Christ set them free by faith (3:1–3). The law had a role, but it was a preparatory role not a final goal. The law was “our schoolmaster to bring us to Christ, that we might be justified by faith. But after faith is come, we are no longer under a schoolmaster” (vv. 25–26, KJV).

God commonly shows us ourselves in the mirror of His law before pointing us to the gospel of His grace. The mirror is good and useful, so long as it is used as a mirror and not as soap and water. That’s when mirrors become dangerous. Let’s look at this mirror of God’s law more closely that we might use it rightly.

God’s law is a constant mirror. With the passing of time, some mirrors lose their sharpness and brightness. Others get damaged and cracked. But God’s moral law never changes, never fluctuates, and never “cracks,” no matter how many years pass or how many stones are thrown at it. God’s moral standards are the same today as they were on day one in Eden.

One of the reasons why human law changes so much is because human law is always flawed. It always leaves loopholes that require constant addition and amendment. But God’s law is perfect. It gives us a flawless picture of God’s perfections and of our imperfections. Some mirrors may flatter us. But this mirror gives us a constantly accurate picture of our spiritual state. The law gives us knowledge of our sin (Rom. 3:20).

God’s law is a complete mirror. Most mirrors only show us parts of our bodies. Even full-length mirrors cannot show us our entire backparts. They certainly cannot show us what is inside us. But God’s law can show us everything — inside and outside. It provides an x-ray into our hearts, motives, and aims.

This will not happen, however, without the Holy Spirit’s work alongside the law. Without Him, God’s law can be heard and repeated a thousand times without once reaching our hearts. For example, when Paul the apostle was Saul of Tarsus he regarded himself as an expert in divine law (Phil. 3:6). However, he had been studying it in the dark. One day the Holy Spirit came and “turned on the light,” with a special spotlight on commandment ten. Until then, he said, he had not really known what sin was (Rom. 7:7). He had heard the tenth commandment many times, but not as he heard it that day. By the enlightening power of the Holy Spirit, the law became a mirror that enabled him to see his own lust-filled heart.

God’s law is a condemning mirror. When the Holy Spirit applies God’s law to our consciences we not only feel uncomfortably guilty, we feel utterly condemned and doomed (Rom. 7:9).

As we have noted, Paul described the law as a “schoolmaster” (Gal. 3:24, KJV). The ES V translates this as “guardian.” However, none of the English versions convey the original concept fully. The word refers to a specific role given to well-educated slaves by wealthy fathers in the Roman Empire. A father would commission such a slave to make sure that his child went to school, kept away from trouble and danger, and completed his studies. The father gave the slave full disciplinary rights over the child, and as the slave’s own life depended on the success of the student, he was often quite brutal in ensuring the student’s compliance.

It was therefore a huge relief for the student when he reached adulthood and was loosed from the slave to become a fully fledged member of the father’s household. Paul is saying to the Galatians: “You are full members of the Father’s household. Why do you want to go back to the harsh slave and his punishment?”

God’s law is a cross-shaped mirror. God’s moral law comprises more than the Ten Commandments. The Ten Commandments summarize God’s moral principles, but these principles are also demonstrated and displayed elsewhere: in God’s providential judgments on nations and individuals, in the life and teaching of Christ, and more. But Christ’s cross reveals God’s law in an unprecedented way. Although the law sends us to the cross, the cross also sends us to the law. The old Scottish professor, James Buchanan, put it like this:

Does not the sinner now feel in his inmost soul, that if Sinai be dreadful, Calvary has its terrors too; that if “by the law is the knowledge of sin,” the Gospel adds its sublime and harmonious commentary; that the cross of Christ is the most awful monument of Heaven’s justice, the most solemn memorial of the sinner’s danger . . . The cross, the cross of a crucified Saviour, is the most powerful, the most impressive demonstration of sin, and righteousness, and judgment.

Buchanan’s point here is that the cross magnifies and amplifies the law and carries home God’s law into the conscience with massive power. At the cross, especially, I see what God thinks of my sin, what God will do with my sin, and what my sin really deserves. But, thankfully, Buchanan does not stop there:

Look once more; for the same cross which wounds will also heal; the same conscience which is pierced by the arrows of conviction may be pacified by the Gospel of peace; and thus all that is terrible in the cross, when combined with the tenderness of God’s mercy, and the amazing, the self-denying, the self-sacrificing love of the Savior, will then only awaken convictions in the conscience, to melt and change them into sweet contrition of heart.

The second use of the law is not to destroy us or to leave us in utter despair. It is to lead us step by step to Christ that we might seek His pardon. Feeling weak and empty-handed, we realize our need for mercy, apply for it, and rest in it. It does not send us to soap, shampoo, and toothpaste, but to the blood of Christ, which alone can cleanse us from sin. Unfortunately, one of the reasons why so many today are reaching for the ineffective soap and toothpaste of their own “good works,” rather than turning to Christ, is that many preachers have hidden God’s holy mirror under a large pile of seeker-sensitive, pew-filling, manpleasing strategies and excuses.

Let’s get God’s mirror out. Let’s polish it. Let’s face it. Let’s be horrified and humbled by what we see in it. And let’s be driven into the welcome embrace of Christ and the blood that washes us whiter than snow.