For I am the Lord your God. Consecrate yourselves therefore, and be holy, for I am holy.  And you shall not make yourselves unclean with any of the swarming things that swarm on the earth. For I am the Lord who brought you up from the land of Egypt to be your God; thus you shall be holy, for I am holy.’”(Leviticus 11:44-45).

...as obedient children, not conforming yourselves to the former lusts, as in your ignorance;  but as He who called you is holy, you also be holy in all your conduct, because it is written, “Be holy, for I am holy” (1 Peter 1:14-16).

The focus in Leviticus is on the handling and eating of clean and unclean animals. The focus in Peter is on moral conduct. The reason for both instructions stem from the same premise, namely, that God's people must be holy because God is holy. 

Holy simply means "set apart". The cognate of this word derives words like "saint" (lit. "set apart ones") and "consecrate" (lit. "to set apart"). Therefore, the command to "be holy" is to be set apart to God, which implies being set apart from something, like unclean animals or immoral conduct.

When Isaiah witnessed the holiness of God, all he could say was,

Woe is me, for I am ruined!
Because I am a man of unclean lips,
And I live among a people of unclean lips;
For my eyes have seen the King, the Lord of hosts” (Isaiah 6:5).

Isaiah immediately sensed the moral gulf between God and himself. Now, we normally have no trouble understanding or accepting this; however, what does various kinds of animals have to do with being holy or unholy?

They have as much to do with holiness as eating a fruit had to do with sin and death for all mankind. Holiness is not bound up in any thing or conduct but in the presence and decree of God. In other words, whatever relates to God is holy. Whatever He commands is holy. 

Consequently, when God forbade eating certain kinds of animals, holiness meant that the people refrain from eating these animals. Yet, when God later permitted eating these very animals, people's holiness was no longer affected by what they ate. What is the important part for us to understand? God, and not the particular command, is what matters. For He can change commands. Yet, His essential holiness does not change.

Let me illustrate with another example. When Israel arrived at Kadesh-Barnea, God commanded them to take the land. He promised to be with them and would give them the land. But the people grumbled in their tents and spoke of returning to Egypt. Then, God gave them a new command. He told them to go back toward the Red Sea and wander around for the next forty years. He would not give them the land at this time. So what did the people do? They went out to fight and take the land.

Were the Israelites being obedient because they repented of their grumbling and chose to obey God's initial command? No. The Bible declares them twice disobedient, stiff-necked and rebellious. The people were not interested in God or what He commanded but simply in their own self-interest. They did not want to wander around for forty years until they died in the desert. So, they decided to ignore God's immediate command and instead follow God's intial command, even though He had retracted it.

Friends, let us understand this about God's holiness. God is holy and good by definition. As the Psalmist writes, "You are good and what you do is good" (Psalm 119:68). There is no inherent holiness or goodness in the commands of God. They are holy and good purely because God issues them. This means that at one moment they can be good and in the next moment evil if God so declares it. When the Psalmist declares, "All your commands are trustworthy," they are trustworthy because God is trustworthy. God defines what is holy and good.

If God declares the dirt to be holy, then the dirt, thereby, becomes holy. You may snicker at this, but I am deadly serious. Didn't God tell Moses and others to take off their shoes because they were standing on holy ground. God was saying that the dirt they were standing on was holy. I, daresay, that if you were to find such a place today, the dirt is no longer holy. It was holy then because God declared it to be so. 

Let us not presume what is holy or unholy, good or evil, apart from what God has said, even what God has said for us now. To discern this, we must carefully study His Word, for not every part of His Word applies to everyone in the same way and for all time. We must discern what is particular and what is universal, what is conditional and what is unconditional, what is temporary and what is enduring. To fail to do this would be both a dangerous presumption and a terrible failure to understand the holiness of God.

Friends,

I have included some good articles that detail a proper way to look at various matters presented in these passages, whether having to do with things that are clean and unclean or matters pertaining to certain diseases, often simply translated as "leprosy" in the text.

I have discovered that rather than appreciating what is written at face value, people have tried to find all kinds of hidden meanings and have carried symbolism beyond what the grammar and the context will allow. I encourage you to resist this temptation. As a basic rule, keep this instruction from Paul in mind: "Do not go beyond what is written":

Now, brothers and sisters, I have applied these things to myself and Apollos for your benefit, so that you may learn from us the meaning of the saying, “Do not go beyond what is written” (1 Corinthians 4:6).

I have included two articles in the Discussion Q & A section that try to explain the significance of the passages on cleanness and uncleanness in the Bible. It treats these subjects very biblically and contextually and would serve as a good model for both laymen and preachers to follow in interpreting passages like what we read today. Here are the links to those articles:

http://bible.org/seriespage/clean-and-unclean-part-i-leviticus-11

http://bible.org/seriespage/offending-god-clean-and-unclean%E2%80%94part-ii-leviticus-12-15

One of the things I believe about all these dietary laws that God is instructing the Israelites not to eat is not that God was a picky eater, but maybe these laws are set up based on the character of the animal's behavior or how they differ from other animals. A pig is dirty, will eat anything, and is never ever clean. A cow on the other hand, is a very clean animal that only eats a certain thing. A typical fish in the water has fins and scales. Something that doesn't would probably not be something you would want to eat anyway. The birds mentioned are pretty much scavengers OR are not what we would consider an ordinary bird! What they would typically eat, we wouldn't want to think about, that is why they are abominations, because what they put in them would also contaminate us. The bugs mentioned that are suitable for eating only eat one thing or another. They wouldn't be polluted. The wouldn't contaminate the person who ate them. They would keep the person's personal "temple" pure. The purpose of these dietary laws is at the end of Ch. 11:

⁴⁴ For I am the Lord your God. You shall therefore consecrate yourselves, and you shall be holy; for I am holy.

Now, a lot of people make heavy waves about the unfairness of God towards women in the OT, but He makes up strict rules for men and women, based perhaps on the severity of the original sin in the Garden. God gave Adam a more severe punishment, although many wouldn't see it that way. Eve's punishment, like her sin, is more physical; Adam's punishment, like his sin, is more spiritual. God burdened Man with a greater responsibility as leaders of their spiritual and physical homes, as I've brought up before. Leadership is not a privilege if you really think about it, it is the burden of the man. God equipped Adam with a spiritual bond to Him, and then when Eve came, Adam lost sight of God's character, followed his wife, and although Eve technically sinned first, Adam's sin was worse because he had a clearer idea of who God was, and he allowed the serpent and his wife to sway him away from God. Adam FOLLOWED her when he should have been leading, because he was SPIRITUALLY stronger. The woman was to be reminded of their sin through childbirth, pain, a menstrual cycle, and their desire is toward her husband, so she burdens her husband with this constant battle for leadership. This is what we should remember when people talk about how unfair God is toward woman.

The Old Testament Law has a lot of interesting expressions. For example, today we read about animals that "divide the hoof" and "chew the cud." Since there is no explanation given as to why these particular animals have been set apart as being unclean, preachers and theologians sometimes take this as a license to make up meanings for them. As long as it sounds sort of plausible, they feel they have been given a free pass to employ this faulty hermeneutic. 

But why risk the judgment of God? God emphasized the importance of not adding or taking away from the Law:

Do not add to what I command you and do not subtract from it, but keep the commands of the LORD your God that I give you (Deuteronomy 4:2)

See that you do all I command you; do not add to it or take away from it (Deuteronomy 12:32).

Yet, don't preachers risk doing this very thing when they "go beyond what is written" (1 Corinthians 4:6) and provide typological or allegorical interpretations for things in Scripture that the Scriptures do not validate?

What does chewing the cud and dividing the hoof have to do with meditating on the Word of God? All who know me know that I would love to teach this, because I believe it is so important to meditate on the Word of God. But I would never teach this from a passage like Leviticus 11, because there is not a hint in the context that this is what God had in mind. If He did, He certainly could have made it clearer to us. Why not just teach it from clear texts like Psalm 1:1-2, where we read,

Blessed is the man... who delight in the law of the LORD 
and meditate on his law day and night.

Or in the New Testament, a passage like 2 Timothy 2:15, where we read,

Do your best to present yourself to God as one approved, a worker who does not need to be ashamed and who correctly handles the word of truth.

Why must we try to give a "spiritual meaning" to everything in Scripture? Must we find a spiritual significance to fins as well? What about the animals that "scurry along"? These are unclean as well. What pray tell spiritual significance does "scurrying" have? This is an appeal to my fellow ministers. Please be reasonable. There is enough in Scripture to preach many lifetimes. We don't have to resort to this sort of folly to tickle the years of God's people. 

Now, if the inspired Biblical writer brings out a typological relationship, that's one thing, but it would be both arrogrant and wrong to confer such authority on ourselves. 

Let's just preach the text. It is sufficient that God commanded that certain types of animals were unclean, and the people of Israel were expected to make such distinctions and to obey God. Let us resist the temptation to read into it more than this. And for preachers who give into this temptation, I encourage every believer to listen to their messages with a grain of salt and to pray for such men because they risk a greater judgment, being accountable for what they preach (James 3:1).

Someone asked an excellent question about the purpose of the food laws, particularly whether good health was one of the primary reasons for them. Here's my response...

Unfortunately, the Bible never gives health as a reason for the food laws. I know that Joel Osteen, the popular pastor out of Houston, gave a whole sermon, where this was his premise. Others have suggested that rather than health the purpose of the food laws was to teach moral discipline. Still others argue that the food laws demonstrate a contrast with the practices of the heathen world that freely eat unclean foods in unclean ways.

While we must always be careful that we are not dogmatic about anything where the Bible is unclear or silent, I think the last reason is closest to the biblical reasoning for the food laws. God said that these regulations, along with numerous others, are to be kept for the sake of His holiness and that they might be a holy people. So we read in Leviticus 11:44-45,

Holy means "set apart" to God. Recall, in Isaiah 6, when confronted with the holiness of God, the prophet cries out in despair because he is a "man of unclean lips living among a people of unclean lips." In both testaments the people of God are called to be morally separate from heathen practices, to be the "salt of the earth." In other words, the things that God prescribes for His people will set them in contrast to the practices of the nations around them. Even in the Book of Revelation we read of the voice from heaven saying, "Come out of her (that is, Babylon), my people, so that you will not share in your sins; so that you will not receive any of her plagues" (Revelation 18:4). Prior to this Babylon was described as "dwelling for demons...a haunt for every unclean bird, a haunt for every unclean and detestable animal" (Revelation 18:2). Babylon was the epitome of godlessness, immorality and greed, and this is how she is described. Therefore, can we surmise that the restrictions on unclean foods and eating practices were meant to contrast the people of God from the heathen nations that surrounded them?

I've read that even authoritative Jewish literature confirms that health was never the biblical reason for the food laws. Michael Friedlander, in his authoritative book The Jewish Religion, writes,

“We must take care that we do not consider these precepts exclusively as sanitary regulations, however important such regulations may be. We must not lose sight of the fact that Holiness is the only object of the Dietary Laws, mentioned in the Pentateuch" (7th Edition; London: Shapiro, Vallentine and Co., 1937).

There are a lot of web sites that draw out particular health benefits from this or that food law. I have not found any comprehensive and most very selective. Therefore, the case for health being a primary reason for the food laws seem flimsy to me.