The Purpose of Old Testament Purity Laws

I was recently asked a question about the Old Testament purity laws. In the Old Testament Mosaic Law there were various things which made a person "unclean". And then there were various means by which that person would become "clean" again. What did it mean to be "unclean"? It essentially meant that one was not permitted to worship God in the temple. Some of the things which made a person unlcean were contact with a dead body, eating certain animals, and even the mere act of sexual intercourse. Often becoming unclean was completely unavoidable. A woman would be unclean during her menstrual period, or for so many days after having a child, for example. And people who had leprosy (which is really all manner of skin rashes and diseases) were unclean, which may have meant that one might be unclean their whole lives! And then certain animals were themselves "unclean", and even certain things could be unclean, such as a mildewy house. Contact with an unclean animal or thing made a person unclean. Since this state of uncleanliness meant that a person was not permitted to enter the temple, it was not a desirable state to be in for one who desired to worship God. So what we want to consider today is "Why?" Why did God set up these laws which banned people from His presence for seemingly trivial, arbitrary and unavoidable things?

This is one area which theologians seem to hold a number of different views. And while I don’t claim to have the answer to every question about these purity laws, I think my understanding of their general purpose is right based on my reading of Scripture. But the first thing I want to establish is that the things which made a person unclean aren’t necessarily sinful! Just consider the things we've looked at... it's not a sin to have a skin disease, or to have a child, or to eat a certain kind of food. None of these things are sinful.

Now, we read in Hebrews that the temple was a sort of "model" of heaven...

For Christ has entered, not into holy places made with hands, which are copies of the true things, but into heaven itself, now to appear in the presence of God on our behalf. (Hebrews 9:24)

Well, if you consider the temple to be a model of heaven, and that being unclean prevented you from entering the temple, then I think we have a good idea of what these purity laws were trying to teach us. The things that made people unclean all seem to have this in common; that they are aspects of life which do not exist in heaven. To have contact with a dead body, (human or animal), made you unclean. Why? Because there’s no death in heaven. People who have skin diseases were unclean because there's no disease in heaven. In fact, leprosy was specifically described as making a person appear "as one dead" (Numbers 12:10-12), and so we can say all the more, should zombie-looking people walk around in this "picture of heaven"? Menstruation, sexual intercourse, or having just given birth; these made you unclean because there's no sex or childbirth in heaven. In Matthew 22:29-30, Jesus says to those who asked a question about marriage in heaven, “...you know neither the Scriptures nor the power of God. For in the resurrection they neither marry nor are given in marriage”. Jesus says they didn't know the Scriptures! But I’m not sure that the Old Testament actually tells us that there is no marriage in heaven unless we interpret the purity laws this way. What we learn from the purity laws are a few things about what humanity will look like after the resurrection.

Now this may not answer every question; there are still some things which appear confusing, and which don't appear to fit my theory. One of these would be the unclean animals. Surely this doesn't fit the model where we can say "some animals won't be present after the resurrection." Common theories are that unclean animals are those animals which often make people sick when they’re eaten. But if that were the case, why would God allow us to eat them now, as though He’s stopped caring for our health? Others say that the unclean animals do have something in common; that they’re all “wilderness animals”. If that were true it might fit my theory because in the New Earth there will be no “wild animals”; all will be domestic. But I’m not sure that this is the way the Bible makes the distinction. It calls animals which “part the hoof but do not chew the cud” unclean. If it were to do with being wild animals, why wouldn’t God just say “wild animals are unclean”? But another view is that the distinction for animals was indeed fairly arbitrary, and only served the purpose of separating Israel from other nations which did eat these things. I think this may be the most Biblical answer, generally speaking at least, when it comes to the purity laws regarding animals. Deuteronomy, whose purpose is to explain the Law, says in the context of reiterating the purity laws for animals:

For you are a people holy to the LORD your God, and the LORD has chosen you to be a people for his treasured possession, out of all the peoples who are on the face of the earth. (Deuteronomy 14:2)

The ultimate purpose for having unclean animals, then, is that God was able to demonstrate the end of the division between Jew and Gentile through the vision of Peter in Acts 10, where God showed that the distinction between animals had been abrogated. In the Old Testament, those laws were designed to separate Jew from Gentile so that a Gentile had to become Jewish if they wanted to worship the true God of Creation. In the New Testament, by taking away this barrier, Jesus is showing us one of the many things His sacrifice on the cross has achieved... a more direct access to God, available to anyone. Whereas all mankind once had to approach God through the mediation of the Jewish priests, now Christ in heaven is our priest, or mediator.

When Jesus came He healed lepers, a woman with a “discharge of blood”, and He raised the dead... all the things which are not sinful but made us unclean, He cleansed. He showed us that He is the one who takes away the corruption of the curse on creation, which was a result of the Fall of Man. Possibly, we aren’t supposed to make sense of the Old Testament laws apart from New Testament revelation. In the New Testament we have a lot of cleansing symbolism - the water of life, the blood of Christ, and baptism. But all of these are “once for all”, as opposed to a regular washing or purification ritual. Now that Christ has come there is no need for priests, for we have direct access to God; and there is no need for purity laws, because Christ has cleansed us. The only notion of a “purity law” in the New Testament is the impurity of sin, and the cleansing away of that sin through repentance and faith in Christ.

But when the goodness and loving kindness of God our Savior appeared, he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit (Titus 3:4-5)