What Does It Mean to be Unclean?

Updated: Apr 24, 2020

Cleanliness, like purity and holiness, is an important subject in the Bible, yet it can be confusing for modern readers—like me. Maybe you too? What does it mean to be unclean? Why were some things or people unclean? Some of the rules seem archaic and obscure. How did a person follow all the rules in everyday life and in varied situations?


For thousands of years, right up to the modern-day, rabbis have been carefully studying and debating exactly how the books of biblical law are to be applied to daily life.


In Jesus' day, the scribes, Pharisees, and Sadducees were the main teachers of how to follow the law. Their “traditions of the elders” built fences around the law to keep people from transgressing and angering God—and they often held these traditions level with the law. (Matthew 14:3) Jesus throws these man-made traditions back in their faces time and time again in the gospels, taking them back to the heart of the law. (Check out all the “you have heard that...but I say to you...” statements in Matthew 5:21-48, and the eight woes in Matthew 23:13-33, for example.)

Do the teachings on being unclean matter to Christians?


Many Christians avoid all the confusing bits of Mosaic law by saying, “it doesn't really apply to us, so why should we worry about it?” I thought that way as well, citing verses like Romans 6:15 as my excuse for being ignorant of the law.


Yet, Jesus grew up under this law. He understood, practiced, and praised the law. (Matthew 5:17-19) Jesus' sacrifice on the cross was the fulfillment of a promise and a plan set in motion from the very beginnings of the Bible. By ignoring the Old Testament are we kicking out the legs from under our understanding of the Christian hope?

For my purposes as a writer, understanding how cleanliness functioned in the first-century world is vital to giving a historically accurate portrayal of how men and women kept pure before God in their daily lives. I long to immerse myself in the world of Jesus, to see the humor, the heartbreak, and the scandals as they would have seen them. This desire makes learning about obscure laws fun for me because it makes the Bible come alive!

So, what does it mean to be clean or unclean?

In the biblical context, cleanliness has nothing to do with being physically dirty. Many people have looked at the lists of things to be avoided and claimed that God was doing this for the people's physical well being. For example, if not cooked properly, pork can make you very ill. However logical these assertions may be, physical health is not the reason given in the scriptures.


The instructions given in the Bible for cleanliness are laid out in the aftermath of Nadab and Abihu and their disregard for following the practices laid out for proper worship. As a result of their arrogant disobedience, these two men are consumed by fire in Leviticus 10:1-7. (It's a shocking story!) God doesn't want this repeated. He warns Aaron about the proper way to approach the tent of meeting so that they will not die,

“and so as to make a distinction between the holy and the profane, and between the unclean and the clean” - Leviticus 10:10

After instructing about clean and unclean animals, God again tells them why:

“For I am the Lord who brought you up from the land of Egypt to be your God; thus you shall be holy, for I am holy.” - Leviticus 11:35

After giving laws on cleanliness among people, God says,

“Thus you shall keep the sons of Israel separated from their uncleanliness, so that they will not die in their uncleanliness by defiling my tabernacle that is among them.” - Leviticus 15:31

Cleanliness, like purity and holiness, is about being in a proper state before God so that we can approach Him. Just as God had the priests consecrate the articles and the tabernacle in Exodus 40:9 so they would be holy (which means set apart for God's use), so the people are to be made holy.

So what things were considered unclean?

Foods could be unclean.

You can read a list of the unclean animals in Leviticus 11. It includes various mammals, fish, birds, and insects. The people must not eat them or even touch their carcasses. Whoever touches the carcass of an unclean animal must wash their clothes and they are unclean until evening. (Leviticus 11:28, 17:15)

Anything that the carcass falls on is also unclean and must be put in water. The item remains unclean until evening, including wooden articles, clothes, skins, or sacks. Ovens or stoves must be broken. If the dead unclean animal falls into an earthenware vessel, it must be smashed. If it falls on seeds for sowing that has water on them, that seed is unclean. (So watch where you swat that fly!)

If an animal that is raised for food dies, the carcass becomes unclean until evening, and the one who picks up the carcass or eats it must wash their clothes and be unclean until evening.

Leprosy was unclean.

The disease we call leprosy today is very specific. In the Bible, leprosy referred to many kinds of skin problems. If a person had a “swelling, or a scab or a bright spot, and it becomes an infection of leprosy on the skin of his body, then he shall be brought to Aaron the priest or to one of his sons.” (Leviticus 13:2) The priests would examine the mark and decide if it warranted quarantine, and would make follow up checks.