Does God’s Moral Standard Change?

By Andrew V. Ste. Marie

“God is not a man, that he should lie; neither the son of man, that he should repent” (Numbers 23:19a), Moses declared.  Indeed, God cannot change; “Jesus Christ the same yesterday, and to day, and for ever” (Hebrews 13:8).  This is a truth which is clear in Scripture.

How, then, can some affirm that God could have changed His standard of conduct for man?  How would it be possible for God to require more of His children in the New Testament than He required of the Israelites, under the Law of Moses?  How could God change His law divinely revealed to Moses at Mount Sinai?

This very argument is urged against those who believe that the New Testament gives a radically higher code of conduct than the Old Testament – for instance, regarding divorce, remarriage, war, oaths, etc.  Those who use this argument continue to follow Moses’ instructions regarding these topics under the assumption that since God never changes, His instructions to the children of Israel through Moses must still be binding for Christians today.  What light does the Bible shed on this argument?

God’s Requirements Do Change

A careful investigation of the Scriptures will reveal that God’s requirements – His instructions to mankind – do indeed change if the situation of mankind changes.  God’s own standard of morality – what He had in mind from the beginning as the standard of perfection – His ultimate, perfect will for mankind – never changes.  However, what He actually does require of man differs based on mankind’s situation.  When God commands something different, it is because something about man changed – not because God changed.

Meat-Eating

Let us examine the different sets of instructions which God had given to different people at different times.  When Adam and Eve were first created, God gave the following instructions:

And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.  And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat.  And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so (Genesis 1:28-30).

God gave Adam and Eve three commandments: 1) Multiply, 2) have dominion over the rest of creation, and 3) eat plants.  Following the Fall of man and throughout the pre-Flood era, God never took back or changed His instructions regarding the eating of plants and not meat.  It is quite likely that sinful, disobedient men did eat meat without God’s permission and it is certain that animals did so,[1] but God had not changed His instructions as far as we know from Scripture.

However, following the Flood, God gave this set of instructions to Noah and his descendants:

And God blessed Noah and his sons, and said unto them, Be fruitful, and multiply, and replenish the earth.  And the fear of you and the dread of you shall be upon every beast of the earth, and upon every fowl of the air, upon all that moveth upon the earth, and upon all the fishes of the sea; into your hand are they delivered.  Every moving thing that liveth shall be meat for you; even as the green herb have I given you all things.  But flesh with the life thereof, which is the blood thereof, shall ye not eat (Genesis 9:1-4).

Notice that now, following the Flood, the flesh of animals is given as food just as plants had been given earlier.  Did God’s moral standard change?  No; the situation of mankind changed, as the post-Flood climate seems to have been much different from the pre-Flood climate, and animal proteins and fats were now needed for survival and growth.  In other words, God did not change; man’s situation changed.  Does God’s change in instructions somehow challenge God’s unchanging nature?  Apparently it does not; the unchanging God gave a different set of instructions, showing us that these facts do not contradict in His infinite wisdom.

The Law of Moses

At a later time in history, God gave a complete set of laws to His chosen people, Israel.  The Law of Moses, given on Mt. Sinai, contained rules concerning moral, ceremonial, religious, civil, environmental, and hygienic behavior.  Up to this time, this was the fullest revelation of God’s will and plan for mankind, and He intended for the Israelites to prosper in obedience to this revelation:

I have heard the voice of the words of this people, which they have spoken unto thee: they have well said all that they have spoken.  O that there were such an heart in them, that they would fear me, and keep all my commandments always, that it might be well with them, and with their children for ever!…Ye shall observe to do therefore as the LORD your God hath commanded you: ye shall not turn aside to the right hand or to the left.  Ye shall walk in all the ways which the LORD your God hath commanded you, that ye may live, and that it may be well with you, and that ye may prolong your days in the land which ye shall possess (Deuteronomy 5:28b-29, 32-33).

Why was the Law of Moses given?  The Apostle Paul wrote:

Wherefore then serveth the law?  It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator (Galatians 3:19).

The Law was given because of transgression – because of sin.  However, it was only intended to be a temporary solution to the problem of sin.  Notice that Paul said the Law was added “till the seed should come”.  The context reveals that the “seed” of whom Paul is speaking is Christ (Galatians 3:16).

The Israelites accepted the obligations in the Law of Moses, and God promised that He would not break the covenant He had made with Israel (Judges 2:1).

The Law’s Moral Teachings

So what were the moral requirements contained in the Law of Moses?  If it is true that God’s standard of morality never changes, what commandments contained in Moses’ law would we still be under the obligation of keeping?

War was commanded under the Law of Moses (Numbers 25:16-18; 31:1-4; Deuteronomy 7:1-3; commandments regarding how war was to be conducted are found in Numbers 10:9; Deuteronomy 20:1-20).  Divorce and remarriage were allowed (Deuteronomy 21:10-14; 22:13-29; 24:1-4).  The swearing of oaths was commanded under certain circumstances (Exodus 22:10-12; Numbers 5:19-22; Deuteronomy 6:13-15; 10:20-21).

It is commandments like these which our Protestant friends wish to keep living under when they insist that God’s moral requirements never change.  They wish to keep their war, their patriotism, their divorce and remarriage, and their oaths.  However, they are not consistent in respect to obeying the Law of Moses.  There are many moral teachings contained in the Law of Moses which few, if any, Protestants or Evangelicals obey.

For instance, while Protestants (rightly) reject outright polygamy,[2]^{, [3]} the Law of Moses actually accepted it, with some restrictions:

And if a man sell his daughter to be a maidservant, she shall not go out as the menservants do.  If she please not her master, who hath betrothed her to himself, then shall he let her be redeemed: to sell her unto a strange nation he shall have no power, seeing he hath dealt deceitfully with her.  And if he have betrothed her unto his son, he shall deal with her after the manner of daughters.  If he take him another wife; her food, her raiment, and her duty of marriage, shall he not diminish.  And if he do not these three unto her, then shall she go out free without money (Exodus 21:7-11).

If a man have two wives, one beloved, and another hated, and they have born him children, both the beloved and the hated; and if the firstborn son be hers that was hated: Then it shall be, when he maketh his sons to inherit that which he hath, that he may not make the son of the beloved firstborn before the son of the hated, which is indeed the firstborn: But he shall acknowledge the son of the hated for the firstborn, by giving him a double portion of all that he hath: for he is the beginning of his strength; the right of the firstborn is his (Deuteronomy 21:15-17).

Another requirement of the Law of Moses is that men should not trim their beards.  Many Evangelicals are either clean-shaven or have short beards.  Few have long, Mosaicly-prescribed beards.

Ye shall not round the corners of your heads, neither shalt thou mar the corners of thy beard (Leviticus 19:27).

Another requirement not often obeyed is this one regarding the use of fabrics in clothing:

Thou shalt not wear a garment of divers sorts, as of woollen and linen together (Deuteronomy 22:11).

Most professing Christians freely wear clothes made of synthetic/cotton or synthetic/wool cloth.

Another point most professing Christians – who profess to be following the Law’s rules on divorce and remarriage – do not notice or follow is that in the Law, divorce is only allowed to men.  Wives were never permitted to divorce their husbands.  Yet in America today, the majority of divorces are initiated by the wife.[4]

We must note Paul’s words in Galatians 5:3:

For I testify again to every man that is circumcised, that he is a debtor to do the whole law.

James wrote:

For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all (James 2:10).

If we have undertaken to obey the Law of Moses and put ourselves under that yoke, we cannot pick and choose which commandments we wish to obey and ignore the ones we do not wish to obey.  If we are going to obey the Law of Moses, we have to obey the entire Law of Moses!

The New Covenant Prophesied

God had promised not to break the Covenant that He had made with the children of Israel, that is, the Law of Moses (Judges 2:1).  However, He knew that the Old or Mosaic Covenant was not perfect (Hebrews 8:7-8).  The children of Israel, although they had promised to obey and keep the covenant, broke it again and again and again (Jeremiah 31:32; Hebrews 8:9).  A new covenant was needed – and God, through the prophets, told His people that the day was coming when a new covenant would be made.

The first prophet to foretell this new covenant was, surprisingly, Moses himself.

The LORD thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken; According to all that thou desiredst of the LORD thy God in Horeb in the day of the assembly, saying, Let me not hear again the voice of the LORD my God, neither let me see this great fire any more, that I die not.  And the LORD said unto me, They have well spoken that which they have spoken.  I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him.  And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him (Deuteronomy 18:15-19).

This prophecy of Christ and His teachings (which is explicitly applied to Christ by the apostles – Acts 3:22-32, 7:37-38) foretold that this Prophet would be like Moses, would be an Israelite, and would speak all the words which God commanded Him.  Moreover, it was these words – the words of this Prophet – which all would be obligated to hearken to (hearken means “to hear and obey”).

In what way was Christ like Moses?  How was He more like Moses than any of the other Old Testament prophets?  Moses had authority from God to give new commandments to the people, which they were obligated to obey.  All of the other Old Testament prophets – Isaiah, Jeremiah, Haggai, etc. – pointed back to the Law of Moses for the people’s standard of behavior.  They did not have authority from God to hand down new commandments to the people.  However, Christ had the authority from God to give new commandments – new laws – which then another group of apostles, prophets, and teachers would point back to as the authoritative basis for life in God’s kingdom.  In this way, Christ was like Moses.

The rest of the prophets, while pointing back to the Law of Moses as authoritative for their time, yet pointed forward to a new day, when the Prophet like unto Moses would institute a new covenant.  This new covenant – and the new revelation of the kingdom of God which would accompany it – was foreseen to have ethical teachings distinctively different from those of the Law of Moses.  Isaiah prophesied:

And it shall come to pass in the last days, that the mountain of the LORD’s house shall be established in the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it.  And many people shall go and say, Come ye, and let us go up to the mountain of the LORD, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the LORD from Jerusalem.  And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more (Isaiah 2:2-4).

This prophecy foresees the spiritual house of the Lord (I Peter 2:5) which would be established in the last days.  “Many people” would be attracted by this new revelation of God’s plan and purpose for man, a veiled prophecy of the coming of the Gentiles to faith in God and obedience to the new covenant.  It was foretold that this new law would come out of Jerusalem and the land of Israel, as actually occurred when the Twelve Apostles and others spread out from the land of Israel, taking God’s new covenant Word all across the then-known world.  Finally, in this age, the Lord would “judge among the nations” and “rebuke many people.”  This new covenant age would affect far more than just the nation of Israel, as had been the case with the Old Covenant.  God’s rebukes and reproof would have their effects for the Gentiles as well.  And what would be the effects of these judgments and rebukes?  War and carnal fighting would cease, just as Jesus and the Apostles taught.[5]

Isaiah later prophesied:

And the Redeemer shall come to Zion, and unto them that turn from transgression in Jacob, saith the LORD.  As for me, this is my covenant with them, saith the LORD; My spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed’s seed, saith the LORD, from henceforth and for ever (Isaiah 59:20-21).

The work of the Redeemer – the Messiah – would be to turn the descendants of Jacob away from transgression.  Then the Lord – the Father – gives a description of the New Covenant: The words which He would command the Messiah to speak would never depart from His mouth, or from the mouth of His spiritual seed, forever.  These words – the words of the Messiah – would be repeated forever.  They would be the lasting message which God wants repeated.  We must obey and teach these words (for other prophesies by Isaiah regarding the new covenant, see Isaiah 42:1-10; 49:8; and 55:3).

The prophet Jeremiah also foretold of the new covenant.  In Jeremiah 31:31-34, we read:

Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the LORD: But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.  And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.

This new covenant would be “not according to the covenant that I made with their fathers.”  It would be a covenant of laws written on the heart, rather than on tables of stone.  We must learn from the words which Christ taught, the words of the new covenant, rather than the words of the old covenant written on tables of stone.

Did Jesus Change the Moral Requirements?

Finally, the Messiah Himself came.  Jesus said, “The law and the prophets were until John: since that time the kingdom of God is preached, and every man presseth into it” (Luke 16:16).  He came and preached the gospel of the kingdom and the new covenant which was to govern it.  So to answer the question, “did Jesus change the moral requirements given in the Law of Moses?”, we must go to the primary source: Jesus’ words themselves.  A comparison of the moral teachings of the Mosaic Law with those of Jesus and His Apostles shows clearly the difference between them.

Sword

Moses said: “If men strive…And if any mischief follow, then thou shalt give life for life, Eye for eye, tooth for tooth, hand for hand, foot for foot, Burning for burning, wound for wound, stripe for stripe” (Exodus 21:22a, 23-25).  Jesus said:

Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.  And if any man will sue thee at the law, and take away thy coat, let him have thy cloke also.  And whosoever shall compel thee to go a mile, go with him twain.  Give to him that asketh thee, and from him that would borrow of thee turn not thou away (Matthew 5:38-42).

War

Moses said:

When the LORD thy God shall bring thee into the land whither thou goest to possess it, and hath cast out many nations before thee, the Hittites, and the Girgashites, and the Amorites, and the Canaanites, and the Perizzites, and the Hivites, and the Jebusites, seven nations greater and mightier than thou; And when the LORD thy God shall deliver them before thee; thou shalt smite them, and utterly destroy them; thou shalt make no covenant with them, nor shew mercy unto them (Deuteronomy 7:1-2).

Jesus summarized the Law’s teaching on neighbors and enemies (the enemy portion is a summary, not a direct quote), then went on to give a new teaching:

Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.  But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.  For if ye love them which love you, what reward have ye?  do not even the publicans the same?  And if ye salute your brethren only, what do ye more than others?  do not even the publicans so?  Be ye therefore perfect, even as your Father which is in heaven is perfect (Matthew 5:43-48).

Paul said:

For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ (II Corinthians 10:3-5).

John said:

If any man have an ear, let him hear.  He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints (Revelation 13:9-10).

Polygamy

As we saw above, Moses regulated polygamy, but did not completely forbid it.  Jesus, however, restored marriage to its Edenic state – one man and one woman for life.  He restored marriage to how it was “from the beginning” (Matthew 19:3-9).  Paul reinforces this by stating, “Nevertheless, to avoid fornication, let every man have his own wife, and let every woman have her own husband” (I Corinthians 7:2).

Divorce and Remarriage

As noted above, the Law of Moses allowed a relatively easy divorce for most husbands, and allowed remarriage for most cases of divorce as well.  However, Jesus completely shut that door, leaving only the “fornication clause” as a reason for divorce.  (It is to be noted that neither Jesus nor the Apostles ever allowed remarriage after divorce, for any reason or in any case.)  See Matthew 5:31-32; 19:3-9; Mark 10:1-12; Luke 16:18; Romans 7:2-3; I Corinthians 7:10-16.

Lust

Moses said, “Thou shalt not commit adultery” (Exodus 20:14).  While the Law also forbade coveting another man’s wife, there was no commandment saying that all sexual lust was sinful.  Jesus, however, taught:

Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart (Matthew 5:27-28).

Circumcision

Moses commanded regarding every baby boy born to the Israelites, “And in the eighth day the flesh of his foreskin shall be circumcised” (Leviticus 12:3).  The New Covenant, however, did away with the need for circumcision – a major theme of the Apostle Paul’s writings.  Jesus introduced the new and spiritual circumcision, the fulfillment of the type of the physical action: “And ye are complete in him, which is the head of all principality and power: In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ” (Colossians 2:10-11).

Headcovering

Moses commanded that the high priest should wear a mitre during his duties in the Tabernacle/Temple:

And thou shalt make a plate of pure gold, and grave upon it, like the engravings of a signet, HOLINESS TO THE LORD.  And thou shalt put it on a blue lace, that it may be upon the mitre; upon the forefront of the mitre it shall be.  And it shall be upon Aaron’s forehead, that Aaron may bear the iniquity of the holy things, which the children of Israel shall hallow in all their holy gifts; and it shall be always upon his forehead, that they may be accepted before the LORD.  And thou shalt embroider the coat of fine linen, and thou shalt make the mitre of fine linen, and thou shalt make the girdle of needlework (Exodus 28:36-39).

However, the new covenant introduced a new teaching:

Now I praise you, brethren, that ye remember me in all things, and keep the ordinances, as I delivered them to you.  But I would have you know, that the head of every man is Christ; and the head of the woman is the man; and the head of Christ is God.  Every man praying or prophesying, having his head covered, dishonoureth his head…For a man indeed ought not to cover his head, forasmuch as he is the image and glory of God: but the woman is the glory of the man (I Corinthians 11:2-4, 7).[6]

Oaths

Moses said:

Thou shalt fear the LORD thy God, and serve him, and shalt swear by his name (Deuteronomy 6:13).

And ye shall not swear by my name falsely, neither shalt thou profane the name of thy God: I am the LORD (Leviticus 19:12).

If a man vow a vow unto the LORD, or swear an oath to bind his soul with a bond; he shall not break his word, he shall do according to all that proceedeth out of his mouth (Numbers 30:2).

Jesus said:

Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: But I say unto you, Swear not at all; neither by heaven; for it is God’s throne: Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King.  Neither shalt thou swear by thy head, because thou canst not make one hair white or black.  But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil (Matthew 5:33-37).

James said:

But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation (James 5:12).

Fulfilled

Jesus said:

Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.  For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled (Matthew 5:17-18).

What would it mean to destroy the Law and the prophets?  Jesus did not teach that the Law was useless; He did not claim that it was not a genuine revelation from God; He did not teach that the Law was wicked.  Rather, He came to fulfill the Law.  He taught a new way, in which we would not only do what the Law taught (do not commit adultery) but also the higher righteousness which God desired (do not lust).  He taught a new and higher way, in which the righteousness we act out now (love your enemies) surpasses the righteousness demanded by the Law (thou shalt utterly destroy them).  Thus, Paul said, “For Christ is the end of the law for righteousness to every one that believeth” (Romans 10:4).

Moral and Ceremonial

Protestant reformer John Calvin was not impressed when he encountered the Anabaptists’ teaching that Christians could not be government officials and could not swear oaths.  In response to this, he wrote:

Therefore, there resteth none other evasion, to these enemies of all order, but to say, that God requireth a greater perfection in the Christian Church than he did among the people of the Jews. Now this is very true, touching ceremonies. But that we have any other rule to live by, touching the moral law, as we call it, than had the ancient people, is a false opinion…

Therefore to say that Moses did but half teach the people of Israel to honour and serve God, is a blasphemy, first forged by the Papists, and now renewed by these poor fantasticals, which take for a revelation from heaven, whatsoever fables they have heard of their grandmothers.[7]

Calvin’s claim, that the New Covenant did have more perfect ceremonies, but that the moral law of Moses was still in effect, is still repeated today.  Is this Scriptural?  Is Moses’ Law divided into two parts, one of which was done away by Christ, the other part which is still binding?

There are at least six reasons why this argument does not hold water.

1. Such a division is never mentioned in Scripture.
2. The Mosaic Law is so far-reaching that it is hard to divide all of the laws neatly into just two or three categories.  There are moral teachings (regarding murder, stealing, etc.); there are ceremonial or religious teachings (the sacrifices and temple services); there are civil teachings (commandments regarding jurisprudence, the cities of refuge, etc.); there are hygienic teachings (regarding the proper disposal of waste, the treatment of lepers, etc.); and there are environmental laws (regarding the harvesting of birds and cutting trees).  How are we to neatly divide all of these laws into two or three categories, and then decide which ones apply to us today and which ones do not?
3. Who gets to decide what applies today and what does not?
4. Some laws bridge the gap between moral and ceremonial, and other, requirements.  For instance, lepers were banished from the camp to avoid the contamination of others; this could be called a law regarding hygiene or sanitation.  Yet the ceremony governing the readmittance of the leper into the community upon healing is undoubtedly a ceremonial law.
5. Different types of laws are often intermingled in the same contexts.  For instance, beginning in Deuteronomy 22:5, we have a moral law regarding cross-dressing, which was forbidden.  The next two verses (6-7) have an environmental protection law, regarding the harvesting of birds.  The next verse has a law regarding construction of a new house – a moral commandment, because the reason for the law was “that thou bring not blood upon thine house”.  Verse 9 has a law that “Thou shalt not sow thy vineyard with divers seeds: lest the fruit…be defiled.”  This law does not seem to fit neatly in either the moral or ceremonial categories.  A similar classification-defying law follows in verse 10.  With this mixture of moral, ceremonial, and other types of laws in the same contexts, how are we to declare which apply today and which do not?
6. Finally, the Ten Commandments (with the possible exception of the Fourth Commandment on the Sabbath) are clearly moral commandments.  Yet even these have been “done away” in Christ (II Corinthians 3:6-10).

The Hardness of Your Hearts

Why were the requirements of the Law of Moses lower than what God actually wanted?  The answer is found in the words of Jesus, as He was explaining why His teaching regarding divorce and remarriage was more rigorous than that of Moses.

The Pharisees also came unto him, tempting him, and saying unto him, Is it lawful for a man to put away his wife for every cause?  And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female, And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?  Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.  They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away?  He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.  And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery (Matthew 19:3-9).

Why did Moses allow things which were outside the perfect will of God, and which Jesus did away with?  Because of the hardness of the Israelites’ hearts.  If they had soft hearts, responsive to God’s will and the voice of His Spirit and willing to obey, God could have given the Israelites the commandments He gave through His Son.  Why could He not?  They had hard hearts – and it is not within man’s power to change his own heart from a hard heart to a soft, living one.  Death is the consequence of sin, and when man’s spirit dies, he cannot resurrect it himself.  Christ came that we might have life again (John 10:10).  God had promised that the hard hearts of the Old Covenant would be replaced, under the New Covenant, with soft, fleshy hearts (Ezekiel 11:19-21).  We learn in the New Testament that this soft heart is God’s own heart – His own Spirit – His own nature – imparted to us (see, for instance, II Peter 1:4).  Thus, with Christ Himself living within us, we are enabled to live as He did in the world and show the world what kind of Being God is.  For instance, we are now enabled to treat our enemies well, just as God does (Matthew 5:45, 48; Luke 6:35-36).

Summary

God’s ultimate standard of right and wrong – what He had in mind originally for man – never changes.  However, His instructions to man do change based upon changes in man’s situation.  For instance, the change brought about by the global Flood brought about a change in God’s instructions regarding diet.  Similarly, the change in heart made possible by the work of Christ is accompanied by a change in the moral requirements God has given to His people.  Whereas Moses, because of the hardness of the Israelites’ hearts, allowed divorce, remarriage, war, oaths, polygamy, etc., Christ forbids these and teaches a higher level of ethics for His children.  Those who have soft, spiritual hearts and have entered the New Covenant will submit to these requirements which Jesus communicated.