by Jeffrey W. Hamilton

Students of the Bible are frequently confused by the Old Testament laws regulating uncleanness. Many do not understand the purpose of the laws and often wonder if they impact the Christian in some way or not. The concept of unclean is certainly an old one. It predates Moses, being first mentioned in the days of Noah when he carried onto the ark both clean and unclean animals (Genesis 7:2). So just what makes some animals clean and others not clean?

If you examine a list of the things labeled as unclean under the Law of Moses, you will find a list of things most people find gross:

• Dead bodies (Leviticus 5:2; 17:15-16);
• Human waste (Leviticus 5:3);
• Certain animals, fish, birds, and insects – particularly those which willingly eat dead things (Leviticus 11:4-23; 29-30);
• Giving birth to children (Leviticus 12:2, 5);
• Diseases that cause a discharge or cause the decaying of the skin (Leviticus 13:3, 8, 14-15; 15:2-3);
• Certain molds or things which cause a material to decay (Leviticus 13:47-51);
• Semen (Leviticus 15:16; Deuteronomy 23:10);
• Menstruation (Leviticus 15:19);
• Improper sexual relations (Leviticus 20:21; Numbers 5:19); and
• Impure actions of people (Ezra 9:11).

These are things to which many people naturally react with disgust at seeing or smelling. The rules regarding unclean things did keep the Israelites away from things which caused disease. Following the rules did cut down on the spread of diseases. But that wasn’t what the laws of uncleanness were fully about.

Uncleanness Represented Sin

God wanted the Israelites to “distinguish between holy and unholy, and between unclean and clean” (Leviticus 10:10). Unclean is the opposite of holy. The two could not be intermixed (Leviticus 11:43-45). Something holy is a treasured item; something set aside for special use, especially for use in the service of God. Something unclean is at the opposite end of the spectrum. These are the things that you don’t want or that you find disgusting, such as detestable things in Deuteronomy 14:3. They are the things which have no value to you.

The fact that Israel distinguished between holy and unclean things made them different from the nations around them. Because they avoided unclean things, they became a special people, a holy people, set apart for a special purpose by God (Leviticus 20:25-26). By keeping themselves from impure things, they became a people acceptable to God (Deuteronomy 23:14).

It is important to realize that the things labeled unclean were not sinful in and of themselves. Breaking the laws regarding uncleanness was a sin, but the items designated as unclean were not necessarily themselves sinful. For example, a pig is a dirty, smelly animal that willingly eats disgusting things. Meat from a pig is not sinful, but eating ham would have been a sin under the Old Testament law.

There was a purpose behind the laws of uncleanness. While the things themselves were not necessarily sinful, they gave the people of Israel a tangible way to understand the concept of sin. By selecting things whose nature was disgusting or without value, God illustrated that sin is disgusting and without value in life. There is no sin in God (I John 1:5-7) and when we sin, we make ourselves vile and disgusting.

The Laws of Uncleanness Illustrated the Nature of Sin

A person became unclean when they came in contact with the unclean (Leviticus 11:24). Though the person is not the unclean thing, contact with it caused its “uncleanness” to spread. Such is the nature of sin. Contact with sin has an impact on you whether you want it or not. Even a priest became unclean in the process of creating the waters used to purify a person from their uncleanness (Numbers 19:6-10). The unclean were separated from the clean to hinder the spread of uncleanness. We realize today that God was teaching man that there must be a separation between the sinful and the righteous; otherwise, sin spreads (II Corinthians 6:14-7:1).

Something clean became unclean on contact. The unclean thing did not become clean when it contacted the clean (Leviticus 7:19; 11:32-35; 15:4-12). Such is the nature of sin. Good things can become corrupt when sin is involved, but sin can never be made right. Evil companions will corrupt the good morals of a person (I Corinthians 15:33). But a good person cannot make an evil person good by casual contact.

If you think about it, uncleanness was hard to stop. Anything or anyone an unclean person contacted became unclean. Thus if it is not dealt with quickly, it would spread like wildfires. Uncleanness could not be ignored. The same is true regarding sin. It spreads from person to person. Ignoring it leaves sin to spread unchecked. This is why Paul scolded, “Your glorying is not good. Do you not know that a little leaven leavens the whole lump?” (I Corinthians 5:6). This is why God has charged all men with sin. “Therefore, just as through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned” (Romans 5:12). It is not that sin is gained through inheritance. It spreads like a disease from one person to another, mostly because it is left unchecked.

Contact with the unclean made you unclean whether you intended to contact it or not. “Or if a person touches any unclean thing, whether it is the carcass of an unclean beast, or the carcass of unclean livestock, or the carcass of unclean creeping things, and he is unaware of it, he also shall be unclean and guilty. Or if he touches human uncleanness -- whatever uncleanness with which a man may be defiled, and he is unaware of it -- when he realizes it, then he shall be guilty” (Leviticus 5:2-3). That is why we need to be concerned about presumptuous sins (Psalms 19:13). Just because we assumed that an action was proper or that we were unaware that it was sinful, it doesn’t make the action any less sinful. People do sin in ignorance, but it doesn’t make it right (Ephesians 4:17-23). Saying, “It was an accident!” doesn’t excuse the sin.

Some things made a person unclean because of a choice that they made, such as the eating of pork. Others were forced upon a person because they had to do what was right, such as burying a body. It was a sin to leave the dead unburied, but the act of burying a body caused you to become unclean. But to emphasize the universal nature of sin, some things selected for uncleanness were things people could not avoid, such as bodily functions. Everyone spent some part of their lives unclean, no matter how hard they might try to avoid it. It is just like sin. “But we are all like an unclean thing, and all our righteousnesses are like filthy rags; we all fade as a leaf, and our iniquities, like the wind, have taken us away” (Isaiah 64:6). Perhaps this should help us understand that when it comes to sin, none of us can claim to be without sin (Romans 3:23). “If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar, and His word is not in us” (I John 1:8-10).

Because uncleanness was easily spread, while a person was unclean they were required to be isolated from the rest of the community (Leviticus 13:44-46; 15:31). They were even required to shout to warn others away. In the same manner, we need to wake up to the poisonous spread of sin. It is more contagious than the worse disease you can imagine. That is why Paul insisted that Christians not keep company with sinful members of the church (I Corinthians 5:9-11). The purpose is to reduce the rate at which sin spreads. “Do you not know that a little leaven leavens the whole lump? Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened” (I Corinthians 5:6-7).

The Difficulty of Becoming Clean

Job points out a fact about uncleanness, “Who can bring a clean thing out of an unclean? No one!” (Job 14:4). You cannot make something clean by using something unclean. For the same reason, you cannot create righteousness from something that is sinful. Oh, that people would learn that you cannot improve a relationship by telling a lie! Paul pointed out this fallacy as well, “And why not say, "Let us do evil that good may come"? --as we are slanderously reported and as some affirm that we say. Their condemnation is just” (Romans 3:8).

This is why mankind could not save itself. We already noted that sin had spread to all of mankind. Someone sinful cannot make someone else righteous because you cannot create righteousness with sin. That is why it took the sinless Son of God to save mankind (II Corinthians 5:21). Thus we were redeemed by the one sinless life available to us (I Peter 1:18-20).

In order for an unclean person to become clean, it took a clean person to administer the rights.

“A clean person shall take hyssop and dip it in the water, sprinkle it on the tent, on all the vessels, on the persons who were there, or on the one who touched a bone, the slain, the dead, or a grave. The clean person shall sprinkle the unclean on the third day and on the seventh day; and on the seventh day he shall purify himself, wash his clothes, and bathe in water; and at evening he shall be clean. But the man who is unclean and does not purify himself, that person shall be cut off from among the assembly, because he has defiled the sanctuary of the LORD. The water of purification has not been sprinkled on him; he is unclean. But the man who is unclean and does not purify himself, that person shall be cut off from among the assembly, because he has defiled the sanctuary of the LORD. The water of purification has not been sprinkled on him; he is unclean. Whatever the unclean person touches shall be unclean; and the person who touches it shall be unclean until evening” (Numbers 19:18-22).

Read that passage carefully and notice that in the process of helping a person become clean, the clean person becomes unclean! The process did not make a person instantly clean. Both the unclean and the clean person were considered unclean until the end of the day. Perhaps this makes Paul’s warning concerning sin clearer. “Brethren, if a man is overtaken in any trespass, you who are spiritual restore such a one in a spirit of gentleness, considering yourself lest you also be tempted” (Galatians 6:1). Sin spreads rapidly and easily. Even while we work to help a person out of their sin we expose ourselves to sin and face the danger of falling into sin ourselves.

In order for an unclean person to become clean, he was required to wash himself (Numbers 19:12, 17). Even if the cause of uncleanness could not be seen, washing was required to remove the uncleanness. This foreshadows baptism. Christians are purified by washing (Ephesians 5:25-26). The act of baptism washes away sins (Acts 22:16). Even though sins are not a physical presence on the body, the act of obedience cleanses the sinner. “There is also an antitype which now saves us -- baptism (not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ” (I Peter 3:21). The result is a new person, dead to the old ways of sin and alive to Christ (Romans 6:3-7).

An important aspect of uncleanness is that an unclean person could not serve or offer worship to God (Leviticus 7:20-21; 22:3; Numbers 9:10). In the same way, a sinner cannot serve or worship God. God does not hear the prayers of the sinner (John 9:31; Proverbs 15:29; 28:9). Therefore, before a person can approach God, they must first cleanse themselves of their unrighteousness. “Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water” (Hebrews 10:22). If we desire to be with God in heaven, then we purify ourselves of sin (I John 3:2-3). And that purified state gives us confidence before God (I John 3:21-22). We need cleansing from sin if we are ever to serve God in this world or the next. Sin cannot be allowed to remain in our lives.

Even after being purified by the water of purification, a sacrifice was often required before the formerly unclean person could return to society (Leviticus 14:19-20; 16:15-16). In regards to sin, Jesus offered himself as the necessary sacrifice (Hebrews 10:5-14; Ephesians 5:1-2). But that is not the only sacrifice involved. We too are expected to offer ourselves as a living sacrifice (Romans 12:1-2). Thus, when Christians sin, all God asks of us is to confess our sins before we are restored to fellowship with God (I John 1:8-10).

Uncleanness in the New Testament

The idea of uncleanness did not disappear with the Old Testament. It remains in the law of Christ but in a modified form. As taught in the Old Testament, uncleanness remains the opposite of holiness. “For God did not call us to uncleanness, but in holiness” (I Thessalonians 4:7). Instead of using external, physical things, the focus in the New Testament shifts to the things which makes the soul unclean (Mark 7:18-23).

While many of the items selected in the Old Testament were things people naturally found disgusting or useless, we realize that the things themselves were not sinful. It was the breaking of the laws in regards to handling uncleanness that was sinful. A pig has a dirty lifestyle and is willing to eat anything. It became the poster animal for uncleanness. But a pig isn’t sinful. Eating pork was a sin under the Old Testament, but the pig itself wasn’t sinful. Those laws of physical uncleanness came to an end with the end of the Old Testament (Colossians 2:13-17). God cleansed the animals used for food (Acts 11:6-9). All meats are now sanctified (I Timothy 4:4-5). Nothing is unclean of itself, but it can become an unclean thing for an individual (Romans 14:14).

Under the New Testament uncleanness now refers to the effect sin has on a person; it dirties the person’s spirit (Romans 6:19). That is what the word translated as “unclean” from the Greek means. Akatharsia refers to moral impurity or things that dirty the mind. While all sins dirty a person, “uncleanness” is generally reserved for those sins that particularly sully a person’s character. That is why you find demons being called unclean spirits. They were evil spirits who caused the person they occupied to misbehave in various ways and sullied that person’s character.

Sexual sins, in particular, are placed under the category of unclean because of the impact they have on the sinner (I Corinthians 6:18-20). The body is to be the temple of God; therefore, it is sanctified or set apart for a holy purpose. But sexual sins dirty the very thing that is supposed to be kept holy (I Thessalonians 4:3-7).

You will often find uncleanness in lists with other sexual sins (II Corinthians 12:21, Galatians 5:19, Colossians 3:5). You will frequently find words with broader meaning included with words of specific meaning in lists. Fornication technically includes adultery in its meaning, but it covers more sinful actions than adultery. When used in a list with adultery, fornication takes on the meaning of sexual acts outside the bounds of marriage but not including adultery. Uncleanness is a broader term than fornication. Thus in Romans 1:24-25, “Therefore God also gave them up to uncleanness, in the lusts of their hearts, to dishonor their bodies among themselves, who exchanged the truth of God for the lie, and worshiped and served the creature rather than the Creator, who is blessed forever. Amen,” “uncleanness” refers to all sexual sins. It is not just restricted to acts of sexual intercourse outside of marriage, it also includes acts that lead to sin or encourage sin, especially sexual sin. Sins of uncleanness are the things that ought to be disgusting to someone trying to live a holy life. Without being graphic, sins of uncleanness in regard to sex are the things a number of people are willing to do that ought to make people go “Ewwh!” at that very idea. Sadly, their minds are so dirtied by sin that they don’t see it as a problem.

Uncleanness is also connected to the idea of covetousness because personal desire or greed is often the motivation behind these sins. “Who, being past feeling, have given themselves over to lewdness, to work all uncleanness with greediness” (Ephesians 4:19).

Uncleanness, along with actual sexual sins, is not to be associated with Christians (Ephesians 5:3-7). Christians are not to be involved in “dirty talk,” “crude jokes,” or “sexual jokes” because these dirty both the speaker and the hearer – filling the mind with improper thoughts and ideas.

God has called us to a holy life (I Peter 1:13-16). Such a life precludes having anything to do with the filth of sin. Though sin still creeps into our lives, we actively work against sin (I Peter 5:8-10). Are you doing something about the filth in your life? Or, are you allowing uncleanness to sully your character unchecked? It is my prayer that understanding the concept of uncleanness in both the Old and New Testament will encourage you to diligently seek out a holy life.