Being clean is the natural state of humans. We are born clean,* but we each become unclean many different ways. One can become unclean through ordinary, normal, necessary and good things. For example, a woman becomes unclean after childbirth (Leviticus 12:1) and during menstruation (Leviticus 15:19-24). Men become unclean after any seminal discharge (Leviticus 15:16). Both men and women become unclean after sexual relations (Leviticus 15:18). Sex and seminal discharges are necessary acts to carry out God’s mandate to “be fruitful and fill the earth” (Genesis 1:28). Childbirth is a blessing from God (Psalm 127:3). Yet, these acts make one unclean.
People also become unclean when they enter an unclean house (Leviticus 14:46-47) or touch something else that is unclean, which at times can be unavoidable (i.e. touching a dead animal [Leviticus 11:39] or a dead person [Numbers 19:11-13]). Men and women both become unclean when they have abnormal discharges and anyone who touches something they had been sitting on or laying on while unclean also becomes unclean (see Leviticus 15).
Another serious form of uncleanness comes from various skin diseases, commonly translated as leprosy (see Leviticus 13). This was so serious because if one had one of these diseases he was unclean and could not live in the camp. “The leprous person who has the disease shall wear torn clothes and let the hair of his head hang loose and he shall cover his upper lip and cry out, ‘Unclean, unclean.’ He shall remain unclean as long as he has the disease. He is unclean. He shall live alone. His dwelling shall be outside the camp” (Leviticus 13:45-46). He might never be rid of the disease and thus would be cut off from the tabernacle and the worship of God all his life.
Other serious forms of uncleanness came through blatant and egregious sins such as adultery (Leviticus 18:20), sacrificing children to Molech (Leviticus 18:21), homosexuality (Leviticus 18:22) and bestiality (Leviticus 18:23).
*Note that women become unclean after they give birth (see Leviticus 12), but there is no mention of the baby being unclean (unlike Hittite laws). See Allen Ross’s chapter, “Holiness and the Physical Life: Childbirth and Purification” in Holiness to the Lord: A Guide to the Exposition of the Book of Leviticus (Grand Rapids: Baker Academic, 2002), especially p. 270.
Other posts in this series
Cleansing from Defilement, Part 1: Introduction
Cleansing from Defilement, Part 2: The Danger of Defilement
Cleansing from Defilement, Part 3: Distinguishing between the Clean and Unclean
Cleansing from Defilement, Part 4: What Makes One Unclean?
Cleansing from Defilement, Part 5: Uncleanness is Contagious and Defiles the Camp
Cleansing from Defilement, Part 6: Defilement and Purity in the New Testament
Cleansing from Defilement, Part 7a: Jesus Christ Makes Us Clean
Cleansing from Defilement, Part 7b: Jesus Christ Makes Us Clean by His Baptism
Cleansing from Defilement, Part 7c: Jesus Christ Makes Us Clean by His Death and Resurrection
Cleansing from Defilement, Part 8: The Incarnation Was Necessary for Our Cleansing