The rules about ceremonial cleanness and uncleanness set Israel apart from other nations. One idea is that unclean things relate to death or the earth (see, for example, Leviticus 21:1, 11; 22:8). Recent studies suggest the idea of what is "normal." God values order. Things that fit God's order are "clean" and "permitted." Abnormal things are not suitable for food or offerings and are "unclean."
A normal land animal would eat plants (see Genesis 1:30). A normal human body would have no infections or discharges. A normal piece of cloth would be free of mildew. If something abnormal happened, the animal, person, or cloth was unclean.
What is unclean is not sinful but represents unworthiness and cannot touch what is holy (for example, Leviticus 11:44–45). Once cleansed, it can become holy and dedicated to God. If people treat holy things, like the Sabbath, as common, they show disrespect to (or blaspheme) God and make it unholy. When something clean becomes unclean, it needs cleansing. Some things, like unclean animals, fish, or birds, are always unclean and can never become holy.
In the new covenant, things once considered unclean are now clean (Acts 10:15, 28, 45). Yet, God values order and wants orderly worship (1 Corinthians 14:33, 40). God offers grace to those who repent (turn away from wrong actions and return to God). Yet, some actions still offend his holiness and should not be in his presence (for example, Ananias and Sapphira’s offering; see Acts 5:1–11).
Passages for Further Study
Genesis 7:2; Leviticus 11:1–15:33; 21:1–23; 22:3–8; Numbers 19:1–22; Deuteronomy 14:1–21; 21:1–9; Psalms 19:9; 24:3–4; 51:7–10; Isaiah 52:11; Matthew 8:2–4; John 13:10–11; Acts 10:9–28; Hebrews 9:13–15, 23