The Contagion of Sin and the Contagion of Grace Text: Numbers 19:20-22
Introduction: The Logic of Pollution
We live in a world that is fastidious about certain kinds of pollution and completely oblivious to others. Our age is terrified of germs, of carbon, of unpasteurized milk, and of politically incorrect statements. We have a highly developed, albeit secular, sense of ritual purity. We wash our hands constantly, we recycle with religious devotion, and we excommunicate people from public life for using the wrong pronouns. But what our world is blind to, what it refuses to see, is the fundamental pollution of sin. It acknowledges the shadow but denies the substance.
The ceremonial laws of the Old Testament can seem strange to us, even bizarre. We read about the ashes of a red heifer, water for impurity, and uncleanness through touching a corpse, and we are tempted to file it away under "ancient curiosities." But this is a grave mistake. These laws are not arbitrary. They are a divine picture book, a physical grammar given to Israel to teach them spiritual realities. They were the schoolmaster, training God's people to understand the logic of two things: the holiness of God and the defilement of sin. Specifically, this chapter in Numbers deals with the most potent form of ceremonial uncleanness, that which comes from contact with death. And death, we must remember, is the wages of sin. Contact with death was a tangible reminder of what sin does. It separates. It defiles. It corrupts.
The modern man thinks he has outgrown all this. He thinks sin is an outdated concept, a tool of oppression. But in his frantic efforts to cleanse the world of all other impurities, he demonstrates that he cannot escape the logic God has written into the fabric of creation. He knows things are not right. He knows there is a stain that needs to be removed. He just misidentifies the stain and proposes a ridiculous remedy. He tries to wash away the guilt of the human heart with paper straws and diversity seminars. It is like trying to cure leprosy with a bar of soap. What we have in our text is God's diagnosis of the problem and the Old Covenant prescription for it. It is a prescription that, as we will see, was always intended to point to a greater, final, and perfect cleansing.
The Text
‘But the man who is unclean and does not purify himself from uncleanness, that person shall be cut off from the midst of the assembly because he has made the sanctuary of Yahweh unclean; the water for impurity has not been splashed on him; he is unclean. So it shall be a perpetual statute for them. And he who sprinkles the water for impurity shall wash his clothes, and he who touches the water for impurity shall be unclean until evening. Furthermore, anything that the unclean person touches shall be unclean; and the person who touches it shall be unclean until evening.’
(Numbers 19:20-22 LSB)
Willful Defilement and Its Consequence (v. 20)
We begin with the solemn warning in verse 20:
"‘But the man who is unclean and does not purify himself from uncleanness, that person shall be cut off from the midst of the assembly because he has made the sanctuary of Yahweh unclean; the water for impurity has not been splashed on him; he is unclean.’" (Numbers 19:20)
Notice the structure of the problem here. The initial problem was not the uncleanness itself. Becoming ceremonially unclean through contact with a dead body was, in many cases, unavoidable. People die. Loved ones must be buried. This was a part of life in a fallen world. The law made gracious provision for this. The ashes of the red heifer, mixed with living water, were God's appointed remedy for this defilement. The sin, the high-handed transgression, was not in becoming unclean, but in remaining unclean. It was the refusal to be purified that constituted the rebellion.
To be "cut off from the midst of the assembly" is the Hebrew word kareth. It means excommunication, to be severed from the covenant people. It was to be treated as a spiritual amputee. Why was the punishment so severe? Because this was not a matter of personal hygiene. The text tells us the reason: "because he has made the sanctuary of Yahweh unclean." An unclean person, walking around in a state of willful defiance, was a walking biohazard to the holiness of God's dwelling place. His presence in the camp was an act of contempt against the Holy One who dwelt in their midst. To treat your own defilement lightly was to treat God's holiness lightly. It was to say, "My impurity is no big deal, and therefore, God's purity is no big deal." This is cosmic treason.
The logic is inescapable. God is holy. His people are called to be holy. Sin, represented here by death-uncleanness, is a contaminant. God, in His grace, provides a means of cleansing. To refuse that cleansing is to despise the grace of God and to profane His holy things. It is to choose your defilement over God's fellowship. And God says, if you insist on clinging to your defilement, you cannot at the same time cling to My assembly. You must be cut off.
This is a direct rebuke to the modern church's casual attitude toward sin. We have people living in open, unrepentant sin who are welcomed into membership and even leadership. We have dismissed the concept of church discipline as judgmental and unloving. But what God calls loving is to maintain the purity of His sanctuary. To allow willful, unrepentant defilement to remain in the camp is to profane the presence of God. It is to invite His judgment, not His blessing.
The Paradox of Purification (v. 21)
Verse 21 introduces a fascinating paradox that is central to understanding the gospel.
"So it shall be a perpetual statute for them. And he who sprinkles the water for impurity shall wash his clothes, and he who touches the water for impurity shall be unclean until evening." (Numbers 19:21)
Here we see something remarkable. The very water that makes the unclean man clean makes the clean man unclean. The "water for impurity" (or water of separation) was a powerful cleansing agent. It was made from the ashes of a perfectly sacrificed red heifer, a sacrifice that dealt with sin and death. When sprinkled on the defiled person, it restored him to the assembly. Yet, the priest who administered this cleansing water, or anyone who simply touched it, was himself rendered unclean until evening. How can this be? How can the remedy for defilement also be defiling?
This is a beautiful and profound type of the work of Christ. The author of Hebrews makes the connection for us. "For if the blood of goats and bulls, and the ashes of a heifer sprinkling those who have been defiled, sanctify for the cleansing of the flesh, how much more will the blood of Christ... cleanse your conscience from dead works to serve the living God?" (Hebrews 9:13-14). The ashes of the heifer were a picture of the substitutionary atonement of Christ.
On the cross, Jesus Christ, the perfectly clean and spotless one, took all our filth, all our defilement, all our sin upon Himself. He who knew no sin was made sin for us (2 Corinthians 5:21). In the act of cleansing us, He Himself was made unclean in our place. He bore the curse. He was "cut off" outside the camp, bearing our reproach. The remedy for our sin, the holy Son of God, was treated as a sinner so that we, the unclean, could be made clean. The water of impurity was a tangible lesson in imputation. The sin of the unclean man was, in a symbolic sense, transferred to the water, and by extension, to the one who handled it. In the same way, our sin was imputed to Christ, and His perfect righteousness is imputed to us. This is the great exchange of the gospel.
The Contagion of Uncleanness (v. 22)
The final verse underscores a critical principle about the nature of sin and defilement.
"Furthermore, anything that the unclean person touches shall be unclean; and the person who touches it shall be unclean until evening.’" (Numbers 19:22)
Uncleanness is contagious. Holiness, under the Old Covenant, was not. A holy thing that touched a common thing did not make the common thing holy. But an unclean thing that touched a clean thing made the clean thing unclean. Sin spreads. Defilement is an aggressive contagion. You don't catch righteousness by sitting next to a righteous man, but you can certainly be corrupted by bad company.
This is a spiritual reality we ignore at our peril. We live in a culture that is saturated with defilement. The things we watch, the things we listen to, the ideologies we absorb, they are not neutral. They carry a spiritual contagion. The willfully unclean man in Israel was a walking pandemic of defilement. Everything and everyone he touched was compromised. In the same way, unrepentant sin in a person's life, or in the life of a church, does not remain contained. It spreads. It corrupts relationships, it pollutes worship, it defiles the sanctuary.
But this is where the glory of the New Covenant shines brightest. In the Old Covenant, uncleanness was contagious. But in the New Covenant, in the person of Jesus Christ, holiness becomes contagious. When the unclean woman with the issue of blood touched the hem of Jesus' garment, she did not make Him unclean. Rather, His cleanness, His power, His holiness flowed out of Him and made her clean. Jesus touches lepers, and instead of becoming a leper, He makes them whole. He touches a dead body, and instead of becoming defiled, He raises it to life. Jesus Christ is the great reversal. He is the divine anti-contagion. His cleanness is more powerful than our uncleanness. His life is more powerful than our death.
Conclusion: Sprinkled and Clean
So what does this ancient law about ashes and water have to do with us? Everything. You were born unclean. You were born outside the camp, spiritually dead, contaminated by the sin of Adam. And you have compounded that original defilement with your own personal transgressions. By nature, you are unfit to enter the assembly of the saints, unfit for the presence of a holy God.
And God, in His mercy, has provided a cleansing. Not the ashes of a heifer, but the precious blood of His own Son. This is the true water for impurity. The book of Hebrews says that our hearts have been "sprinkled clean from an evil conscience" (Hebrews 10:22). The sacrifice has been made. The cleansing has been provided.
The question for you is the same one that faced the Israelite in our text. Now that the remedy is provided, what will you do? Will you, like the man in verse 20, refuse to be purified? Will you say, "My sin is not so bad. My defilement is my own business"? Will you cling to your filth and therefore despise the sanctuary of God? If you do, the sentence is the same. You will be cut off. Not from a camp in the wilderness, but from the presence of the living God for all eternity. That is what hell is, to be cut off, permanently.
Or will you come to be cleansed? Will you admit your defilement, confess your uncleanness, and flee to the only remedy? The blood of Jesus Christ is the only cleansing agent in the universe powerful enough to wash away the stain of sin. To come to Him in faith is to be sprinkled clean. It is to be welcomed into the assembly. It is to have His contagious holiness begin to work in you, making you clean from the inside out. Do not remain unclean when the fountain has been opened. Come, and be clean.