Did God change his mind regarding Marriage laws?
We would have to say “yes,” since we know that brother and sister marriages would have occurred before the giving of the Mosaic law. Indeed, Abraham rightly claims more than once that Sarah (his wife) was his sister. And yet God later forbids the marriage between brothers and sisters and half-siblings in Leviticus 18:9.
“‘Do not have sexual relations with your sister, either your father’s daughter or your mother’s daughter, whether she was born in the same home or elsewhere.”
We see therefore that marriage laws are not eternal and immutable but can and were changed by God over the course of time. This points to the reality that polygamy likewise, once allowed, is now forbidden and we gather that from the words of Christ as He appeals to the definition of marriage as being between one man and one woman;
Matthew 19:4 “Haven’t you read,” he replied, “that at the beginning the Creator ‘made them male and female,’[a] 5 and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh’[b]? 6 So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.”
Here Jesus is quoting from the monogamy description between Adam & Eve recorded in Genesis,
Then the man said, “This, at last, is bone of my bones and flesh of my flesh; she shall be called Woman because she was taken out of Man.” Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. And the man and his wife were both naked and were not ashamed. Genesis 2:23-25
The teaching of Christ here thus is irrefutable evidence that just as there was a change in marriage laws as applied to siblings so with the words of Christ there is a change against OT polygamous marriage in the NT. This is especially so when Christ’s words are coupled with Paul’s injunction that Church officers are to be the husband of one wife.
Finally, the Scripture suggests that God’s law touching marriage will be altered yet again in the age to come.
29Jesus answered, “You are mistaken because you do not know the Scriptures or the power of God. 30 In the resurrection, people will neither marry nor be given in marriage. Instead, they will be like the angels in heaven.”
So, all this put together teaches that God has the right to change His law fitting to His desire. Of course, God’s law only changes upon God’s authority but where we find God’s authority for a change in the law there we are obliged to own that change in the law.
Scripture clearly demarcates changes in marriage laws that Christians are bound to honor. As such we can say again that polygamy is against God’s Law. This is also the testimony of the Church as seen from countless men of God through history.
[Question] Did God merely permit polygamy in the Old Testament times or was that required?
[Rushdoony] The norm we have in Leviticus 18: I believe its verse 18, yes, Leviticus 18:18: neither shalt thou take a wife, or if you look at your marginal notes if you have a reference, it literally is a wife to another, rather than a wife to her sister, in other words take more than one wife to vex her and so on. Now, what this does is to forbid polygamy but God’s law at the same time regulates polygamy because it recognizes that the sin of men is such that he is going to do certain things, the norm is (monogamous) marriage.
“The question is about the polygamy of the patriarchs in the old testament. Now first of all, lets look at the whole subject from the biblical perspective. From the perspective of the bible, the family is the basic institution of mankind. The family. Therefore, the bible looks at the family as against everything that is hostile to the family, therefore any kind of promiscuity, adultery, anything that is hostile to the family is regarded with total enmity. Now from the beginning, the bible recognizes monogamy as the standard from the garden of Eden. The Mosaic law makes it clear that this is the true path. These other forms are regarded as inferior, defective and more or less sinful forms of the family. But, not as bad anything that is anti-family, thus in our culture today for example, we look on polygamy with horror. ”
Imagination vs. History Lecture
“Polygamy is seen by God as an inferior form of marriage. The law forbids it but also imposes regulations on those who practice it.”
Exodus Commentary — pg. 292
Calvin on Polygamy,
When he soon afterwards adds, that God created them male and female, he commends to us that conjugal bond by which the society of mankind is cherished. For this form of speaking, God created man, male and female created he them, is of the same force as if he had said, that the man himself was incomplete.94 Under these circumstances, the woman was added to him as a companion that they both might be one, as he more clearly expresses it in the second chapter. Malachi also means the same thing when he relates, (Genesis 2:15,) that one man was created by God, whilst, nevertheless, he possessed the fullness of the Spirit.95 For he there treats of conjugal fidelity, which the Jews were violating by their polygamy. For the purpose of correcting this fault, he calls that pair, consisting of man and woman, which God in the beginning had joined together, one man, in order that every one might learn to be content with his own wife.
Calvin’s Commentary on Genesis 2:24
“They shall be one flesh.”
Although the ancient Latin interpreter has translated the passage ‘in one flesh,’ yet the Greek interpreters have expressed it more forcibly: ‘They two shall be into one flesh,’ and thus Christ cites the place in Matthew 19:5. But though here no mention is made of two, yet there is no ambiguity in the sense; for Moses had not said that God has assigned many wives, but only one to one man; and in the general direction given, he had put the wife in the singular number. It remains, therefore, that the conjugal bond subsists between two persons only, whence it easily appears, that nothing is less accordant with the divine institution than polygamy. Now, when Christ, in censuring the voluntary divorces of the Jews, adduces as his reason for doing it, that ‘it was not so in the beginning,’ (Matthew 19:5,) he certainly commands this institution to be observed as a perpetual rule of conduct. To the same point also Malachi recalls the Jews of his own time:
‘Did he not make them one from the beginning? and yet the Spirit was abounding in him.’153 (Malachi 2:15.)
Wherefore, there is no doubt that polygamy is a corruption of legitimate marriage.
The Jamieson, Fausset and Brown commentary states, quoting verse 18 from the Authorized Version: “Neither shalt thou take a wife to her sister, to vex her”:
“The marginal construction involves an express prohibition of polygamy; and, indeed, there can be no doubt that the practice of having more wives than one is directly contrary to the divine will. It was prohibited by the original law of marriage, and no evidence of its lawfulness under the Levitical code can be discovered, although Moses—from ‘the hardness of their hearts’ [Mt 19:8; Mr 10:5]—tolerated it…”
“[I]f Christianity is not to control the laws of the country, then as monogamy is a purely Christian institution, we can have no laws against polygamy, arbitrary divorce, or ‘free love.'”
— Charles Hodge
Note, Polygamy, or the marriage of more persons than one, as well as adultery, must be a breach of marriage-covenants, and a violation of the partner’s rights.
Because god has joined them together (v. 15): Did not he make one, one Eve for one Adam, that Adam might never take another to her to vex her (Lev. xviii. 18), nor put her away to make room for another? It is great wickedness to complain of the law of marriage as a confinement, when Adam in innocency, in honour, in Eden, in the garden of pleasure, was confined to one. Yet God had the residue of the Spirit; he could have made another Eve, as amiable as that he did make, but, designing Adam a help meet for him, he made him one wife; had he made him more, he would not have had a meet help. And wherefore did he make but one woman for one man? It was that he might seek a godly seed—a seed of God (so the word is), a seed that should bear the image of God, be employed in the service of God, and be devoted to his glory and honour,—that every man having his own wife, and but one, according to the law, (1 Cor. vii. 2), they might live in chaste and holy love, under the directions and restraints of the divine law, and not, as brute beasts, under the dominion of lust, and thus might propagate the nature of man in such a way as might make it most likely to participate of a divine nature,—that the children, being born in holy matrimony, which is an ordinance of God, and by which the inclinations of nature are kept under the regulations of God’s command, might thus be made a seed to serve him, and be bred, as they are born, under his direction and dominion.
Note from Reformed Study Bible for the account of Lamech in Gen. 4:19-24
19 And Lamech took unto him two wives: the name of the one was Adah, and the name of the other Zillah.
Lamech represents both a progressive hardening in sin with his defiant embrace of polygamy.
Here’s how the original Geneva Bible phrased it:
The lawful institution of marriage, which is, that two should be one flesh, was first corrupted in the house of Cain by Lamech.
We will end with Scripture again
Deuteronomy 17:17 Neither shall he multiply wives for himself, lest his heart turn away;
The addition of wives, Scripture teaches, leads to men’s hearts being turned away from God. This is as true for men who are not kings as for men who are kings (the context of Deut. 17:17).
And we see that as the record of the OT where polygamy is never mentioned without there being a strife and conflict in the home where it was practiced.
Having pointed all this out we would have to conclude that those who continue to insist on the continued validity of polygamy are practicing antinomians on this subject and have need to repent and bow to God’s revelation.