The Divine Diagnosis: When a Scar Is Not a Scar Text: Leviticus 13:18-23
Introduction: God's Diagnostic Manual
We live in a therapeutic age, which is another way of saying we live in a dishonest age. We have exchanged the priest for the therapist, the confessional for the couch, and the diagnosis of sin for the language of brokenness, trauma, and dysfunction. The modern world wants a God who is a divine butler, a cosmic affirmation machine, but it has no room for a God who is a holy physician, a God who diagnoses, isolates, and cuts out spiritual disease. And so, when we come to a passage like this one in Leviticus, our first impulse is to dismiss it as part of an arcane and irrelevant purity code. We think it has to do with primitive hygiene, not theology.
But this is a profound mistake. The laws concerning leprosy in Leviticus 13 and 14 are not primarily about public health. They are a detailed, physical picture of a far more serious spiritual reality. Leprosy, in the Old Testament, is the premier type and shadow of sin. It is a living death. It corrupts from the inside out, it isolates, it spreads, and it makes a man unclean, unfit to dwell in the presence of a holy God. And just as physical leprosy required the careful, objective diagnosis of a priest, so also does the spiritual leprosy of sin require the careful, objective diagnosis of God through His Word and His appointed ministers.
The world tells you to look inside yourself for the truth. It tells you that your feelings are the ultimate arbiter of reality. If you feel clean, you are clean. If you feel good about yourself, then all is well. But God's Word comes to us with the sharp, antiseptic smell of the physician's office. It tells us that self-diagnosis in spiritual matters is the ultimate act of folly. A man with leprosy cannot declare himself clean. He must present himself to the priest. He must submit to an external, objective standard. Our passage today deals with a particularly insidious case: a boil that has healed, but in the place of the old wound, a new and more dangerous infection threatens to break out. This is a powerful picture of the deceptive nature of sin, the danger of superficial healing, and the necessity of a divine diagnosis.
The Text
“When the body has a boil on its skin and it is healed, and in the place of the boil there is a white swelling or a reddish-white bright spot, then it shall be shown to the priest; and the priest shall look, and behold, if it appears to be lower than the skin, and the hair on it has turned white, then the priest shall pronounce him unclean; it is the infection of leprosy; it has broken out in the boil. But if the priest looks at it, and behold, there are no white hairs in it, and it is not lower than the skin and is faded, then the priest shall isolate him for seven days; and if it spreads farther on the skin, then the priest shall pronounce him unclean; it is an infection. But if the bright spot remains in its place and does not spread, it is only the scar of the boil; and the priest shall pronounce him clean."
(Leviticus 13:18-23 LSB)
The Treacherous Scar (vv. 18-19)
We begin with the presenting condition. A man has had a boil, and it has healed. This is a picture of a past sin, a past spiritual malady that seems to have been dealt with.
"When the body has a boil on its skin and it is healed, and in the place of the boil there is a white swelling or a reddish-white bright spot, then it shall be shown to the priest" (Leviticus 13:18-19)
The problem arises in the very place of the old wound. A scar is supposed to be a sign of healing, a reminder of a battle won. But here, the scar tissue itself becomes suspect. It becomes the breeding ground for a new problem. This is a profound spiritual lesson. Sins that we think are long past and dealt with can be the very places where new, deeper corruptions take root. A man who struggled with anger in his youth might "heal" from it, only to find that in its place a "reddish-white bright spot" of bitter, simmering resentment has grown. A woman who repented of gossip might find in the place of that old boil a "white swelling" of self-righteous judgment against others who gossip. The old sin appears to be gone, but a more subtle, more dangerous, and more leprous sin has taken its place.
Notice the first step. The man must be "shown to the priest." He does not get to make the call himself. He cannot say, "Oh, it's just a scar, it's nothing." The moment there is a question, the moment there is a bright spot in the place of an old wound, it must be submitted to outside, divinely appointed authority. For us, this means we must bring our spiritual condition constantly before our great High Priest, the Lord Jesus, as He is revealed in His Word. We must not trust our own evaluations of our spiritual health. We must allow the Word of God, which is sharper than any two-edged sword, to pierce and to discern the thoughts and intentions of our hearts.
The Objective Criteria (v. 20)
The priest's examination is not based on feelings or intuition. God gives him two clear, objective diagnostic criteria.
"and the priest shall look, and behold, if it appears to be lower than the skin, and the hair on it has turned white, then the priest shall pronounce him unclean; it is the infection of leprosy; it has broken out in the boil." (Leviticus 13:20 LSB)
The first test is depth: is it "lower than the skin?" Sin is never a superficial problem. It is not just a bad habit or a poor choice. True spiritual leprosy, true corruption, is always deep-seated. It goes down to the root of our being. The world's solutions to sin are always cosmetic. They are about managing behavior, improving self-esteem, or changing your environment. But God's diagnosis goes deeper. He asks, "Is this issue rooted in pride? In unbelief? In idolatry?" A mere scar is on the surface. Leprosy has roots.
The second test is its effect on life: has "the hair on it has turned white?" Hair is a sign of life, of vitality. When the hair in the infected spot turns white, it signifies that the disease has corrupted the very source of life in that area. It is turning life into death. This is precisely what sin does. It takes things that God created for life, things like ambition, desire, and speech, and it corrupts them, turning them into instruments of death. Ambition becomes pride. Desire becomes lust. Speech becomes slander. When the very life that springs from a part of our soul is corrupted and dead, that is a sign of spiritual leprosy.
If these two signs are present, the priest's duty is clear. He must "pronounce him unclean." This is not a mean-spirited act. It is an act of faithfulness to God and an act of love to the community. To misdiagnose leprosy, to call the unclean clean, is to endanger the entire camp of God. In the same way, ministers of the gospel have a solemn duty to call sin, sin. To soften the diagnosis, to refuse to pronounce as unclean what God calls unclean, is pastoral malpractice of the highest order.
The Quarantine and the Final Test (vv. 21-23)
But what if the signs are ambiguous? What if it is not obviously deep, and the hairs have not turned white?
"But if the priest looks at it, and behold, there are no white hairs in it, and it is not lower than the skin and is faded, then the priest shall isolate him for seven days; and if it spreads farther on the skin, then the priest shall pronounce him unclean; it is an infection. But if the bright spot remains in its place and does not spread, it is only the scar of the boil; and the priest shall pronounce him clean." (Leviticus 13:21-23 LSB)
In cases of uncertainty, the prescription is quarantine. The man is to be isolated for seven days. This period of waiting is designed to reveal the true nature of the spot. This is a crucial principle for the church in its exercise of discipline and in our own personal sanctification. Sometimes the nature of a sin or a fault is not immediately clear. Wisdom requires patience. A period of observation, of waiting on the Lord, will reveal the truth.
And what is the final, determinative test? It is whether or not the infection spreads. "If it spreads farther on the skin, then the priest shall pronounce him unclean; it is an infection." This is the fundamental nature of sin. Sin is a spiritual cancer. It is never static. It is always metastasizing. A "small" lust, left unchecked, will spread to consume a man's mind, his marriage, and his ministry. A "little" bitterness, left to fester, will spread and defile many. If the problem in your life is growing, if it is conquering new territory, you can be sure it is an active infection of spiritual leprosy.
But if, after the seven days, the spot "remains in its place and does not spread," then the diagnosis is clear. "It is only the scar of the boil; and the priest shall pronounce him clean." A scar is contained. It is a sealed-off memory of a past wound. It does not grow. This is a picture of a sin that has been truly repented of and mortified by the Spirit. The memory may remain. The weakness in that area may still be felt. But the active, spreading power of the sin has been broken. And in that case, the priest has the glorious duty to "pronounce him clean." This is the joy of justification and the assurance of pardon. When Christ, our High Priest, has dealt with our sin, He declares us clean, and we are clean indeed.
The Great High Priest
This entire process is a magnificent portrait of the ministry of the Lord Jesus Christ. We are all born with the leprosy of sin. We are covered in boils and bright spots, our disease is deeper than the skin, and it has corrupted every part of our being. We are utterly unclean, and by ourselves, we can do nothing but cry out, "Unclean, unclean!" and dwell outside the camp, separated from the holy presence of God.
We cannot diagnose ourselves, and we certainly cannot heal ourselves. We must present ourselves to the one true High Priest, Jesus Christ. He is the one who examines us with perfect knowledge. He sees the depth of our corruption. He sees how the leprosy of sin has turned all our life into death.
But here is the glorious difference. The Aaronic priest could only diagnose; he could not cure. He could only touch a clean man to confirm his cleanness. If he touched an unclean man, he would become unclean himself. But when Jesus Christ, our High Priest, came, He did the unthinkable. He reached out and touched the leper. And when He touched the leper, He did not become unclean. The leper became clean.
In Jesus, cleanness has become contagious. He took our uncleanness upon Himself on the cross. He became the leprous one, cast outside the camp, so that we might be brought into the presence of God. He does not just pronounce us clean on the basis of a superficial examination. He goes deeper than the skin. He gives us a new heart. He puts His Spirit within us, and He begins the true work of healing, killing the infection at its root.
Therefore, do not trust your own self-assessment. Do not cover up the bright spots or pretend the old boils are just harmless scars. Bring your whole self to the Great Physician. Submit to the diagnosis of His Word. Let Him examine you. And trust that He who is the only one qualified to pronounce you unclean is also the only one with the power, and the love, to make you clean.