What was the original, practical purpose of the biblical cleanliness laws? Is the original purpose still relevant today? Will it be relevant in the future? The answer to these questions is complex, yet it is simply stated in the following scripture:
Leviticus 15:31
You must keep the Israelites separate from things that make them unclean, so they will not die in their uncleanness for defiling my dwelling place, which is among them.
People didn't just keel over and die for becoming unclean - people became unclean all the time! Women became unclean when they gave birth, and anyone who contracted a skin disease or touched a dead body was unclean. Furthermore, if a person's close relative had died, then the law specifically
permitted people to become physically unclean by touching their loved one's dead body during their mourning. There was an established cleansing process for each type of uncleanness mentioned in the law. Becoming unclean didn't necessarily imply that someone had sinned!
Therefore, in light of these observations, how does Leviticus 15:31 fit into understanding the purpose of cleanliness laws? According to this verse, the Israelites had to avoid becoming unclean because they would die
for defiling God's dwelling place, which was among them. Notice that they did not die merely for becoming unclean, but rather for being unclean
in the dwelling place of God. Therefore, I conclude that the cleanliness laws were a set of physical standards and requirements for being in the PHYSICAL presence of God. The way that God dwelt among the Israelites was not some touchy-feely "God is everywhere" kind of presence - God physically manifested Himself among them as their King, and anyone who did not meet His requirements in His presence would die.