When the Bible talks about ritual purity and laws regarding clean and unclean practises, it’s vitally important to note the social context of such passages in order to attain a clearer understanding.
When it comes to the laws of ritual purity in the Bible, as those held in Leviticus for example, skeptics are often quick to laugh at such laws or call them outdated. What’s missing with such criticisms is an understanding of the social world in which they were upheld. As one who holds social context in high regard when it comes to Biblical studies and exegesis, these laws present the perfect opportunity to explain some of these social concepts.
The ancient world was one which was always bordering on destruction. This constant threat was accompanied by a sense of chaos and disorder. The laws regarding ritual purity were, at their core, purposed to provide order and to aid Israel in returning to the image of a faultless God. Passages such as Leviticus 13:9-13 give us an example of this:
“When the plague of leprosy is in a man, then he shall be brought unto the priest; And the priest shall see him: and, behold, if the rising be white in the skin, and it have turned the hair white, and there be quick raw flesh in the rising; It is an old leprosy in the skin of his flesh, and the priest shall pronounce him unclean, and shall not shut him up: for he is unclean. And if a leprosy break out abroad in the skin, and the leprosy cover all the skin of him that hath the plague from his head even to his foot, wheresoever the priest looketh; Then the priest shall consider: and, behold, if the leprosy have covered all his flesh, he shall pronounce him clean that hath the plague: it is all turned white: he is clean.”
Some have wondered how a man can be deemed clean while being entirely covered with leprosy. The context here and throughout Leviticus is one of ritual purity. That’s not to say there aren’t relationships between physical and ritual cleanliness. Most of the dietary laws themselves reflect both a physical and ritual cleanliness.
Scholar David Desilva in his book, Honor, Patronage, Kinship, and Purity, (a must read for anyone interested in understanding the Biblical social world) describes ritual purity this way:
Purity in the ancient world “is fundamentally concerned with the ordering of the world and making sense of one’s everyday experiences in light of that order, which is usually conceived as being a divine ordering of the cosmos…”
In essence, this was the ancient’s way of reflecting the character of a holy God in a world that was so departed from God’s standard. Anything apart from this was breaching God’s standard of perfection, and so here is born passages such as Leviticus 13 with regards to the leper, and verses such as Leviticus 19:19 which lays out the law of wearing garments of wool and linen together. As this breached the boundary of the divine order, it was seen as unclean and unfit for a worship offering.
This may seem like a case of obsessive-compulsive disorder, but it’s not so far from absurd skeptics will have us believe. A lot of us today hold to these same concepts of ritual purity, even if we do so unconsciously. If you don’t like chewing gum from under the table, or if you’re like me and don’t like mixing peas and corn with your potato, then you too hold to this same concept, although in a much more trivial manner.
In a world on the edge of destruction, these reminders were needed in order to maintain a sense of order, and this order was purposed to reflect a holy deity who was worthy of such unflinching adoration and worship. Anything apart from this order was unfit to be an offering.
For a more detailed analyse of the laws of ritual purity, refer to this article by scholar Joe Sprinkle: http://www.biblestudytools.com/dictionaries/bakers-evangelical-dictionary/clean-unclean.html