Scripture reveals that God created the vast array of animal life that inhabits our planet and further states that some animals were created for the specific purpose of providing food for mankind (1 Timothy 4:3 1 Timothy 4:3Forbidding to marry, and commanding to abstain from meats, which God has created to be received with thanksgiving of them which believe and know the truth.
American King James Version×). Although a Christian is not obligated to eat any meats, vegetarianism in its various forms, if practiced as a matter of religious requirement, is considered to be a spiritual weakness (Romans 14:2 Romans 14:2For one believes that he may eat all things: another, who is weak, eats herbs.
American King James Version×), and trying to impose that as a teaching to others is listed as a "doctrine of demons" (1 Timothy 4:1-3 1 Timothy 4:1-3  Now the Spirit speaks expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;  Speaking lies in hypocrisy; having their conscience seared with a hot iron;  Forbidding to marry, and commanding to abstain from meats, which God has created to be received with thanksgiving of them which believe and know the truth.
American King James Version×).
There is no clear statement as to when God first revealed the difference between those animals that are designated "clean" in Scripture and those that are not. The absence of a clear command on this matter in the first few chapters of Genesis should not be taken as proof that no instruction was given in this regard at the beginning of human history.
There are few clear commands in the early pages of the Bible, but the examples that are recorded reveal that standards of right and wrong were clearly understood. For example, there is no clear command against murder before Cain killed his brother Abel, but no one would conclude that murder was therefore acceptable before this point.
The book of Genesis can be described as a book of beginnings. It was written or compiled by Moses to provide a historical record of what took place, not to list specific laws. Readers shouldn't assume, based on absence from the beginning of Genesis, that any law not mentioned was not in existence from the beginning.
The first statement in Scripture concerning "clean" and "unclean" animals is found in Genesis 7:2 Genesis 7:2Of every clean beast you shall take to you by sevens, the male and his female: and of beasts that are not clean by two, the male and his female.
American King James Version×, where Noah is commanded to take seven (or, more likely, seven pairs) of each kind of clean animal and only one pair of each kind of unclean animal.
When God told Noah to build a giant ark, He gave explicit instructions on its size, composition and design, yet Scripture records that God saw no need to instruct Noah about which creatures were clean and which were unclean. God's instruction and Noah's response clearly indicate that Noah already understood which creatures were clean and which were not.
At the conclusion of the great Flood, God told Noah: "Every moving thing that lives shall be food for you. I have given you all things, even as the green herbs" (Genesis 9:3 Genesis 9:3Every moving thing that lives shall be meat for you; even as the green herb have I given you all things.
American King James Version×). This did not mean, however, that every single animal was fit for human consumption. Many creatures by their very nature are dangerous, poisonous and place our health at risk.
The point being made here was that, even though there were few men left alive, and large and dangerous animals had been preserved, Noah and his family had no need to fear these animals. Animals, the verse makes clear, were to be for man's benefit. As a whole, they were given into man's control in the same way the green plants were given.
Note the parallel. Some green plants are suitable for food, some are suitable for building materials, some are for beautification and enjoyment, and some are poisonous and can sicken and bring death when ingested. In the same way, some animals are useful for providing food while others provide fibers for clothing, strength for working the land or protection from dangers. And like poisonous plants, some animals are not intended to be eaten.
Whenever animals are mentioned in Scripture as a food source or in connection with sacrifice before Israel received the Old Covenant at Mount Sinai, they are invariably animals designated as clean (Genesis 15:9 Genesis 15:9And he said to him, Take me an heifer of three years old, and a she goat of three years old, and a ram of three years old, and a turtledove, and a young pigeon.
American King James Version×—cow, goat, sheep, dove, pigeon; Genesis 22:13 Genesis 22:13And Abraham lifted up his eyes, and looked, and behold behind him a ram caught in a thicket by his horns: and Abraham went and took the ram, and offered him up for a burnt offering in the stead of his son.
American King James Version×—sheep; Exodus 12:5 Exodus 12:5Your lamb shall be without blemish, a male of the first year: you shall take it out from the sheep, or from the goats:
American King James Version×—sheep or goat). The law of clean and unclean meats clearly predates the Old Covenant, regardless of what role they may have played within that covenant.
When the Levitical system was established, it was necessary to codify a number of matters that had already been in effect for some time. Two sections of Scripture, Leviticus 11 and Deuteronomy 14:3-21 Deuteronomy 14:3-21  You shall not eat any abominable thing.
 These are the beasts which you shall eat: the ox, the sheep, and the goat,
 The hart, and the roebuck, and the fallow deer, and the wild goat, and the pygarg, and the wild ox, and the chamois.
 And every beast that parts the hoof, and separates the cleft into two claws, and chews the cud among the beasts, that you shall eat.
 Nevertheless these you shall not eat of them that chew the cud, or of them that divide the cloven hoof; as the camel, and the hare, and the coney: for they chew the cud, but divide not the hoof; therefore they are unclean to you.
 And the swine, because it divides the hoof, yet chews not the cud, it is unclean to you: you shall not eat of their flesh, nor touch their dead carcass.
 These you shall eat of all that are in the waters: all that have fins and scales shall you eat:
 And whatever has not fins and scales you may not eat; it is unclean to you.
 Of all clean birds you shall eat.
 But these are they of which you shall not eat: the eagle, and the ossifrage, and the ospray,
 And the glede, and the kite, and the vulture after his kind,
 And every raven after his kind,
 And the owl, and the night hawk, and the cuckow, and the hawk after his kind,
 The little owl, and the great owl, and the swan,
 And the pelican, and the gier eagle, and the cormorant,
 And the stork, and the heron after her kind, and the lapwing, and the bat.
 And every creeping thing that flies is unclean to you: they shall not be eaten.
 But of all clean fowls you may eat.
 You shall not eat of anything that dies of itself: you shall give it to the stranger that is in your gates, that he may eat it; or you may sell it to an alien: for you are an holy people to the LORD your God. You shall not seethe a kid in his mother's milk.
American King James Version×, codify which creatures are set apart as suitable for food and which are not. The term used to designate those animals whose flesh is acceptable for food is clean, while the term used for those that are not suitable for food is unclean. It is important that we "distinguish between the unclean and the clean" (Leviticus 11:47 Leviticus 11:47To make a difference between the unclean and the clean, and between the beast that may be eaten and the beast that may not be eaten.
American King James Version×; compare Ezekiel 22:26 Ezekiel 22:26Her priests have violated my law, and have profaned my holy things: they have put no difference between the holy and profane, neither have they showed difference between the unclean and the clean, and have hid their eyes from my sabbaths, and I am profaned among them.
American King James Version×; Ezekiel 44:23).
Scripture does not reveal exactly why God designated certain animal flesh as suitable for food while other flesh is not acceptable. There could be health reasons or symbolic reasons or, as there seems to be, both. God certainly knows why and how He created each animal. Yet even if God's determinations in this matter were purely just a test of obedience, He, as the Creator of all life, has full rights to make such decisions.
Various passages in the New Testament show that the laws of clean and unclean meats were still being observed by Jesus Christ and His followers. As eager as the religious leaders of Jesus' day were to accuse Him of violating their interpretations of religious law, there is no record that they ever confronted Him about His teachings or practices on this matter. Had He advocated eating unclean meats, it would have been an ideal way to besmirch His reputation with the masses, since they would have been appalled at such an idea.
Jesus' statement in an oft-misquoted passage in Mark 7:19 Mark 7:19Because it enters not into his heart, but into the belly, and goes out into the draught, purging all meats?
American King James Version×would have outraged the religious leaders had they interpreted it the way many people do today. His reference to purifying all foods here is often thought to refer to Him declaring all meat clean. But His statement actually refers to all foods being purged out of the body through bodily elimination. This has nothing to do with whether meats are considered clean or unclean.
Acts 10 is another commonly misunderstood passage that actually powerfully illustrates the early New Testament Church's understanding about clean and unclean meats—although this is not the primary purpose behind the vision described here.
The apostle Peter received a vision from God that instructed him to take the gospel message to gentiles (non-Israelites). During this vision, Peter three times refused to partake of the unclean animals shown him and remained puzzled about the meaning of the vision until God revealed that it was actually about people and not really about clean and unclean animals. It was revealed to Peter that no human being should be considered "common or unclean" (Acts 10:28-29 Acts 10:28-29  And he said to them, You know how that it is an unlawful thing for a man that is a Jew to keep company, or come to one of another nation; but God has showed me that I should not call any man common or unclean.
 Therefore came I to you without gainsaying, as soon as I was sent for: I ask therefore for what intent you have sent for me?
American King James Version×).
This chapter ends with the Holy Spirit being given to the household of the gentile Cornelius as proof that God's calling to repentance and salvation was now going to people in all nations (Acts 10:44-48 Acts 10:44-48  While Peter yet spoke these words, the Holy Ghost fell on all them which heard the word.
 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
 For they heard them speak with tongues, and magnify God. Then answered Peter,
 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
 And he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days.
American King James Version×; see also Acts 11:1-18 Acts 11:1-18  And the apostles and brothers that were in Judaea heard that the Gentiles had also received the word of God.  And when Peter was come up to Jerusalem, they that were of the circumcision contended with him,  Saying, You went in to men uncircumcised, and did eat with them.  But Peter rehearsed the matter from the beginning, and expounded it by order to them, saying,  I was in the city of Joppa praying: and in a trance I saw a vision, A certain vessel descend, as it had been a great sheet, let down from heaven by four corners; and it came even to me:  On the which when I had fastened my eyes, I considered, and saw four footed beasts of the earth, and wild beasts, and creeping things, and fowls of the air.  And I heard a voice saying to me, Arise, Peter; slay and eat.  But I said, Not so, Lord: for nothing common or unclean has at any time entered into my mouth.  But the voice answered me again from heaven, What God has cleansed, that call not you common.  And this was done three times: and all were drawn up again into heaven.  And, behold, immediately there were three men already come to the house where I was, sent from Caesarea to me.  And the Spirit bade me go with them, nothing doubting. Moreover these six brothers accompanied me, and we entered into the man's house:  And he showed us how he had seen an angel in his house, which stood and said to him, Send men to Joppa, and call for Simon, whose surname is Peter;  Who shall tell you words, whereby you and all your house shall be saved.  And as I began to speak, the Holy Ghost fell on them, as on us at the beginning.  Then remembered I the word of the Lord, how that he said, John indeed baptized with water; but you shall be baptized with the Holy Ghost.  For as much then as God gave them the like gift as he did to us, who believed on the Lord Jesus Christ; what was I, that I could withstand God?  When they heard these things, they held their peace, and glorified God, saying, Then has God also to the Gentiles granted repentance to life.
American King James Version×). Although this section of Scripture has been used to claim permission to eat unclean animals, it clearly indicates the opposite. The event here took place several years into the history of the New Testament Church, yet Peter rejected the idea of eating unclean meat, even going so far as protesting that he had "never eaten anything that is common or unclean" (Acts 11:14 Acts 11:14Who shall tell you words, whereby you and all your house shall be saved.
American King James Version×).
Paul, in a passage cited earlier, wrote of creatures "which God created to be received with thanksgiving by those who believe and know the truth" and described these creatures as "sanctified by the word of God and prayer" (1 Timothy 4:3-5 1 Timothy 4:3-5  Forbidding to marry, and commanding to abstain from meats, which God has created to be received with thanksgiving of them which believe and know the truth.
 For every creature of God is good, and nothing to be refused, if it be received with thanksgiving:
 For it is sanctified by the word of God and prayer.
American King James Version×).
The word used to describe these creatures, sanctified, means "set apart," and it carries the dual connotation of being set apart from something as well as for something. The only animals set apart by the Word of God, the Bible, are those listed in it as clean. They have been set apart from all other animals and for man's nourishment. The flesh of those creatures designated as suitable for food is to be received thankfully by those who believe and know the truth. Animal flesh designated as unclean is unfit for human consumption and should not be eaten.
God gave other important food laws as well. He declares as a perpetual statute that His people eat neither fat nor blood (Leviticus 3:17 Leviticus 3:17It shall be a perpetual statute for your generations throughout all your dwellings, that you eat neither fat nor blood.
American King James Version×; Leviticus 7:22-26; Leviticus 17:10-14; Leviticus 19:26; Deuteronomy 12:16 Deuteronomy 12:16Only you shall not eat the blood; you shall pour it on the earth as water.
American King James Version×; Deuteronomy 12:23-25 Deuteronomy 12:23-25  Only be sure that you eat not the blood: for the blood is the life; and you may not eat the life with the flesh.  You shall not eat it; you shall pour it on the earth as water.  You shall not eat it; that it may go well with you, and with your children after you, when you shall do that which is right in the sight of the LORD.
American King James Version×; Deuteronomy 15:23; 1 Samuel 14:33-34 1 Samuel 14:33-34  Then they told Saul, saying, Behold, the people sin against the LORD, in that they eat with the blood. And he said, You have transgressed: roll a great stone to me this day.  And Saul said, Disperse yourselves among the people, and say to them, Bring me here every man his ox, and every man his sheep, and slay them here, and eat; and sin not against the LORD in eating with the blood. And all the people brought every man his ox with him that night, and slew them there.
American King James Version×; Ezekiel 33:25 Ezekiel 33:25Why say to them, Thus said the Lord GOD; You eat with the blood, and lift up your eyes toward your idols, and shed blood: and shall you possess the land?
American King James Version×). The forbidden fat referred to is that of mammals, not birds, and it is the covering fat that could be removed rather than the fat marbled in the meat.
The blood restriction applies to mammals and birds. The requirement that blood be drained from any meat before eating it was even communicated by the New Testament apostles to gentile converts accustomed formerly to eating strangled animals not drained of blood (Acts 15:19-20 Acts 15:19-20  Why my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
 But that we write to them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
American King James Version×, Acts 15:28-29 Acts 15:28-29  For it seemed good to the Holy Ghost, and to us, to lay on you no greater burden than these necessary things;  That you abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if you keep yourselves, you shall do well. Fare you well.
American King James Version×). As God says in Deuteronomy 12:25 Deuteronomy 12:25You shall not eat it; that it may go well with you, and with your children after you, when you shall do that which is right in the sight of the LORD.
American King James Version×, "You shall not eat it, that it may go well with you and your children after you, when you do what is right in the sight of the Lord."