Is there tension between the NT and the OT with regard to sexual immorality?

[Wheat Field]

According to christianity.com a concubine is defined as:
'A woman acquired by a man as a secondary wife. Her purpose was to provide a male heir in the case of a barren wife, to provide more children in general to enhance the family’s workforce and wealth, and to satisfy the man’s sexual desires. A concubine was endowed with rights and protections by Hebrew law but was not equal in status to a wife'.

We know that both Abraham and Kind David had concubines. I am not aware of any OT scripture that explicitly condemns such behaviour.

Genesis 25:6
But while he was still living, he gave gifts to the sons of his concubines and sent them away from his son Isaac to the land of the east.

2 Samuel 5:13
After he left Hebron, David took more concubines and wives in Jerusalem, and more sons and daughters were born to him.

Now when we come to the NT we have this from Paul:
1 Corinthians 6:9-10
Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.

 

[Free]

According to christianity.com a concubine is defined as:
'A woman acquired by a man as a secondary wife. Her purpose was to provide a male heir in the case of a barren wife, to provide more children in general to enhance the family’s workforce and wealth, and to satisfy the man’s sexual desires. A concubine was endowed with rights and protections by Hebrew law but was not equal in status to a wife'.

We know that both Abraham and Kind David had concubines. I am not aware of any OT scripture that explicitly condemns such behaviour.

Genesis 25:6
But while he was still living, he gave gifts to the sons of his concubines and sent them away from his son Isaac to the land of the east.

2 Samuel 5:13
After he left Hebron, David took more concubines and wives in Jerusalem, and more sons and daughters were born to him.

Now when we come to the NT we have this from Paul:
1 Corinthians 6:9-10
Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.

We have to be very careful in taking specific passages that refer to polygamy without also considering them within the overarching story of marriage in Scripture. First, we have the command of God to Adam and Eve, using the singular "wife":

Gen 2:24 Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. (ESV)

That is the normative prescription for marriage that carries throughout the Bible. Then we come across the first polygamist in the Bible:

Gen 4:19 And Lamech took two wives. The name of the one was Adah, and the name of the other Zillah.
...
Gen 4:23 Lamech said to his wives: “Adah and Zillah, hear my voice; you wives of Lamech, listen to what I say: I have killed a man for wounding me, a young man for striking me.
Gen 4:24 If Cain's revenge is sevenfold, then Lamech's is seventy-sevenfold.” (ESV)

It is important to note that Lamech was very wicked, which implies that his having more than one wife is morally wrong, as it is not in keeping with the command God gave to Adam and Eve. Then we have the seventh commandment and sex outside of marriage:

Exo 20:14 “You shall not commit adultery. (ESV)

Given what is stated in Gen 2:24, this would prohibit multiple wives and sexual partners. Jesus appeals to that commandment but shows what it really means:

Mat 5:27 “You have heard that it was said, ‘You shall not commit adultery.’
Mat 5:28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. (ESV)

On a side note, this is because sin isn't necessarily an action; it's a matter of the heart, where all sin begins (Matt 15:18-19).

Then, regarding the kings of Israel:

Deu 17:17 And he shall not acquire many wives for himself, lest his heart turn away, nor shall he acquire for himself excessive silver and gold. (ESV)

What do we see with David? David took multiple wives and concubines, something the Law said he wasn't supposed to do, and his polygamy led to murder and the breaking up of his house. Never is polygamy condoned in the Bible and is often put in a negative light. Abraham's polygamy came with a high cost as well (Gen 16:11-12).

Jesus gives what is the normative teaching regarding marriage throughout Scripture:

Mar 10:5 And Jesus said to them, “Because of your hardness of heart he wrote you this commandment.
Mar 10:6 But from the beginning of creation, ‘God made them male and female.’
Mar 10:7 ‘Therefore a man shall leave his father and mother and hold fast to his wife,
Mar 10:8 and the two shall become one flesh.’ So they are no longer two but one flesh. (ESV)

It is important to see that Jesus argues right back to creation as to the ideal for marriage. Paul also does so here, in speaking of marriage but also makes the parallel to Christ and the Church:

Eph 5:31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.”
Eph 5:32 This mystery is profound, and I am saying that it refers to Christ and the church. (ESV)

Paul's appeal to Gen 2:24 also includes the singular "wife." This is what Paul states is necessary for elders and deacons:

1Ti 3:2 Therefore an overseer must be above reproach, the husband of one wife, sober-minded, self-controlled, respectable, hospitable, able to teach,
...
1Ti 3:12 Let deacons each be the husband of one wife, managing their children and their own households well. (ESV)

Tit 1:5 This is why I left you in Crete, so that you might put what remained into order, and appoint elders in every town as I directed you—
Tit 1:6 if anyone is above reproach, the husband of one wife, and his children are believers and not open to the charge of debauchery or insubordination. (ESV)

Lest anyone think that is only for leaders in the Church, that is also seen regarding all believers in general:

1Co 7:1 Now concerning the matters about which you wrote: “It is good for a man not to have sexual relations with a woman.”
1Co 7:2 But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.
1Co 7:3 The husband should give to his wife her conjugal rights, and likewise the wife to her husband. (ESV)

Notice that once again Paul is speaking in the singular regarding a man having a wife and a woman having a husband.

Putting that all together then, the Bible is prescriptive in teaching that marriage is between one man and one woman, and that is the only morally acceptable situation for sexual relations. God allowed some in the OT to have multiple wives and concubines, but that is descriptive, never prescriptive. And it is almost always, if not always, put in a negative light.

Here is a good article on this subject (where I got some of the above): https://www.desiringgod.org/articles/why-did-god-allow-polygamy

 

[Hidden In Him]

Now when we come to the NT we have this from Paul:
1 Corinthians 6:9-10
Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.

Did Paul regard Abraham and King David as wicked men?

 

[Wheat Field]

We have to be very careful in taking specific passages that refer to polygamy without also considering them within the overarching story of marriage in Scripture. First, we have the command of God to Adam and Eve, using the singular "wife":

Gen 2:24 Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. (ESV)

That is the normative prescription for marriage that carries throughout the Bible. Then we come across the first polygamist in the Bible:

Gen 4:19 And Lamech took two wives. The name of the one was Adah, and the name of the other Zillah.
...
Gen 4:23 Lamech said to his wives: “Adah and Zillah, hear my voice; you wives of Lamech, listen to what I say: I have killed a man for wounding me, a young man for striking me.
Gen 4:24 If Cain's revenge is sevenfold, then Lamech's is seventy-sevenfold.” (ESV)

It is important to note that Lamech was very wicked, which implies that his having more than one wife is morally wrong, as it is not in keeping with the command God gave to Adam and Eve. Then we have the seventh commandment and sex outside of marriage:

Exo 20:14 “You shall not commit adultery. (ESV)

Given what is stated in Gen 2:24, this would prohibit multiple wives and sexual partners. Jesus appeals to that commandment but shows what it really means:

Mat 5:27 “You have heard that it was said, ‘You shall not commit adultery.’
Mat 5:28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. (ESV)

On a side note, this is because sin isn't necessarily an action; it's a matter of the heart, where all sin begins (Matt 15:18-19).

Then, regarding the kings of Israel:

Deu 17:17 And he shall not acquire many wives for himself, lest his heart turn away, nor shall he acquire for himself excessive silver and gold. (ESV)

What do we see with David? David took multiple wives and concubines, something the Law said he wasn't supposed to do, and his polygamy led to murder and the breaking up of his house. Never is polygamy condoned in the Bible and is often put in a negative light. Abraham's polygamy came with a high cost as well (Gen 16:11-12).

Jesus gives what is the normative teaching regarding marriage throughout Scripture:

Mar 10:5 And Jesus said to them, “Because of your hardness of heart he wrote you this commandment.
Mar 10:6 But from the beginning of creation, ‘God made them male and female.’
Mar 10:7 ‘Therefore a man shall leave his father and mother and hold fast to his wife,
Mar 10:8 and the two shall become one flesh.’ So they are no longer two but one flesh. (ESV)

It is important to see that Jesus argues right back to creation as to the ideal for marriage. Paul also does so here, in speaking of marriage but also makes the parallel to Christ and the Church:

Eph 5:31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.”
Eph 5:32 This mystery is profound, and I am saying that it refers to Christ and the church. (ESV)

Paul's appeal to Gen 2:24 also includes the singular "wife." This is what Paul states is necessary for elders and deacons:

1Ti 3:2 Therefore an overseer must be above reproach, the husband of one wife, sober-minded, self-controlled, respectable, hospitable, able to teach,
...
1Ti 3:12 Let deacons each be the husband of one wife, managing their children and their own households well. (ESV)

Tit 1:5 This is why I left you in Crete, so that you might put what remained into order, and appoint elders in every town as I directed you—
Tit 1:6 if anyone is above reproach, the husband of one wife, and his children are believers and not open to the charge of debauchery or insubordination. (ESV)

Lest anyone think that is only for leaders in the Church, that is also seen regarding all believers in general:

1Co 7:1 Now concerning the matters about which you wrote: “It is good for a man not to have sexual relations with a woman.”
1Co 7:2 But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.
1Co 7:3 The husband should give to his wife her conjugal rights, and likewise the wife to her husband. (ESV)

Notice that once again Paul is speaking in the singular regarding a man having a wife and a woman having a husband.

Putting that all together then, the Bible is prescriptive in teaching that marriage is between one man and one woman, and that is the only morally acceptable situation for sexual relations. God allowed some in the OT to have multiple wives and concubines, but that is descriptive, never prescriptive. And it is almost always, if not always, put in a negative light.

Here is a good article on this subject (where I got some of the above): https://www.desiringgod.org/articles/why-did-god-allow-polygamy

Thanks for this Free.

The problem with linking polygamy with wickedness as with Lamech is that it does not hold for King David. God considered David a 'man after his own heart' who 'had done nothing wrong except in the case of Uriah the Hittite'.

Acts 13:22
After removing Saul, he made David their king. God testified concerning him: ‘I have found David son of Jesse, a man after my own heart; he will do everything I want him to do.’

1 Kings 15:5
For David had done what was right in the eyes of the Lord and had not failed to keep any of the Lord’s commands all the days of his life—except in the case of Uriah the Hittite.

If David kept the Lord's commands for everything other than Bathsheba and Uriah, then he must have done what was right when he took more concubines and wives. The opportunity to group David's polygamy along with his sin against Uriah is right there in 1 Kings 15; it remains astonishing that doesn't happen.

Also, it is an inference to attribute the downfall of David to his polygamy rather than specifically to his adultery with Bathsheba.

I read through the page you linked to and would take issue with this from it:
"The Song of Solomon poetically unfurls the glory of marriage and sex in a way that lauds complementarian monogamy".

On the contrary, what we actually have is a man (presumably Solomon) seeking out yet another woman (the Shulammite) in addition to his 140 wives and concubines (not sure what the reference to virgins means):

Song of Songs 6:8,9
Sixty queens there may be, and eighty concubines, and virgins beyond number; but my dove, my perfect one, is unique, the only daughter of her mother, the favourite of the one who bore her. The young women saw her and called her blessed; the queens and concubines praised her.

 

[Wheat Field]

Did Paul regard Abraham and King David as wicked men?

If we assume Paul wrote Hebrews then he commends them and others for their faith. However, Paul also said (quoting from Psalm 14):
As it is written: “There is no one righteous, not even one; there is no one who understands; there is no one who seeks God. All have turned away, they have together become worthless; there is no one who does good, not even one.” (Romans 3:10-12)

"for all have sinned and fall short of the glory of God,"
(Romans 3:23)

 

[Hidden In Him]

If we assume Paul wrote Hebrews then he commends them and others for their faith. However, Paul also said (quoting from Psalm 14):
As it is written: “There is no one righteous, not even one; there is no one who understands; there is no one who seeks God. All have turned away, they have together become worthless; there is no one who does good, not even one.” (Romans 3:10-12)

"for all have sinned and fall short of the glory of God,"
(Romans 3:23)

Yes, but he regularly made distinctions between righteous and wicked men. And since he spoke well of both (Romans 4:1-8), the argument becomes moot.

 

[Wheat Field]

Yes, but he regularly made distinctions between righteous and wicked men. And since he spoke well of both (Romans 4:1-8), the argument becomes moot.

Could you tell me how this relates to the OP?

It remains curious how we read of many, many instances of men sinning in the OT along with God's punishment, yet despite the command not to commit adultery, we do not see the same pattern with polygamy. It's casually stated as if nothing untoward has happened.

We might trust that there may have been mitigating circumstances - that perhaps wars had left an oversupply of woman who would struggle to make a living without a supporting husband in the culture of the time...but we also might wonder at the taking of concubines for sexual gratification?

Acts 17:11
Now the Berean Jews...received the message with great eagerness and examined the Scriptures every day to see if what Paul said was true.

I, for one, am troubled when I examine the scriptures.

 

[Hidden In Him]

Could you tell me how this relates to the OP?

It remains curious how we read of many, many instances of men sinning in the OT along with God's punishment, yet despite the command not to commit adultery, we do not see the same pattern with polygamy. It's casually stated as if nothing untoward has happened.

We might trust that there may have been mitigating circumstances - that perhaps wars had left an oversupply of woman who would struggle to make a living without a supporting husband in the culture of the time...but we also might wonder at the taking of concubines for sexual gratification?

Acts 17:11
Now the Berean Jews...received the message with great eagerness and examined the Scriptures every day to see if what Paul said was true.

I, for one, am troubled when I examine the scriptures.

Polygamy wasn't the norm in the Old Testament either. It was rare, and generally reserved for rich men who could afford to care for more than one partner. But the teaching in the NT that a presbyter be the "husband of one wife" suggests the possibility existed in the New Testament era as well.

Is it ideal? I think it complicates Christ's teaching that "the two shall become one flesh." But should it be regarded as a sin to end all sins? I don't think that either. Too much is made of it, especially by enemies of our God for tolerating it during OT times. Abraham's case was born out of a desire to fulfill the promise of God and David and Solomon's were because the Israelites insisted on having a king even when God told them not to. But was it a spiritual deal breaker that sent a godly man to Hell? Obviously not. So too much is made of it either way.

 

[Wheat Field]

Polygamy wasn't the norm in the Old Testament either. It was rare, and generally reserved for rich men who could afford to care for more than one partner. But the teaching in the NT that a presbyter be the "husband of one wife" suggests the possibility existed in the New Testament era as well.

Is it ideal? I think it complicates Christ's teaching that "the two shall become one flesh." But should it be regarded as a sin to end all sins? I don't think that either. Too much is made of it, especially by enemies of our God for tolerating it during OT times. Abraham's case was born out of a desire to fulfill the promise of God and David and Solomon's were because the Israelites insisted on having a king even when God told them not to. But was it a spiritual deal breaker that sent a godly man to Hell? Obviously not. So too much is made of it either way.

As noted in the OP, adulterers wont inherit the kingdom of God. Paul actually says: do not be deceived.

1 Corinthians 6:9-10
Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.

God compares the unfaithfulness of Israel with an adulterous wife.

Hosea 1:2
When the Lord began to speak through Hosea, the Lord said to him, “Go, marry a promiscuous woman and have children with her, for like an adulterous wife this land is guilty of unfaithfulness to the Lord.”

Obviously the teaching of scripture is that salvation comes through faith (as in Romans 4) and not works - but a man with more than one wife is clearly not 'loving God with all his heart and all his soul and all his mind'.

 

[Free]

Thanks for this Free.

The problem with linking polygamy with wickedness as with Lamech is that it does not hold for King David. God considered David a 'man after his own heart' who 'had done nothing wrong except in the case of Uriah the Hittite'.

Yes, but my point was only that the first instance of polygamy in the Bible was by someone wicked. David came quite some time later.

Acts 13:22
After removing Saul, he made David their king. God testified concerning him: ‘I have found David son of Jesse, a man after my own heart; he will do everything I want him to do.’

1 Kings 15:5
For David had done what was right in the eyes of the Lord and had not failed to keep any of the Lord’s commands all the days of his life—except in the case of Uriah the Hittite.

If David kept the Lord's commands for everything other than Bathsheba and Uriah, then he must have done what was right when he took more concubines and wives.

Not necessarily. The normative for marriage, for sexual relations, is set out in Gen 2:24. That is held by Jesus and the Apostles, which means that is normative for Christians.

God let all sorts of sins slide, for a time. As with divorce, God allowed certain things because of the hardness of people’s hearts. As I pointed out, there is an explicit command for kings to not take multiple wives in Deut 17:17.

The opportunity to group David's polygamy along with his sin against Uriah is right there in 1 Kings 15; it remains astonishing that doesn't happen.

And it doesn’t mention the specific law that clearly shows David was in the wrong.

Also, it is an inference to attribute the downfall of David to his polygamy rather than specifically to his adultery with Bathsheba.

His polygamy set the pattern for taking any woman he wanted. By disregarding the Law, by breaking the command to not have multiple wives, it made it easier for David to then break the seventh and tenth commandments, which led to breaking the sixth. There is a clear pattern, imo.

I read through the page you linked to and would take issue with this from it:
"The Song of Solomon poetically unfurls the glory of marriage and sex in a way that lauds complementarian monogamy".

On the contrary, what we actually have is a man (presumably Solomon) seeking out yet another woman (the Shulammite) in addition to his 140 wives and concubines (not sure what the reference to virgins means):

Song of Songs 6:8,9
Sixty queens there may be, and eighty concubines, and virgins beyond number; but my dove, my perfect one, is unique, the only daughter of her mother, the favourite of the one who bore her. The young women saw her and called her blessed; the queens and concubines praised her.

Fair enough, but the biblical pattern for marriage approved by God is one man and one woman. There is no other acceptable marital or sexual relationship in Scripture. That the Bible describes certain other sexual relationships is neither implicit approval nor prescription of those things.

 

[1pet2_9]

Back to the OP, yes, I think the OT and NT do have some at-odds moments when it comes to sexual immorality. In the OT, you stoned them.

 

[Josef]

According to christianity.com a concubine is defined as:
'A woman acquired by a man as a secondary wife. Her purpose was to provide a male heir in the case of a barren wife, to provide more children in general to enhance the family’s workforce and wealth, and to satisfy the man’s sexual desires. A concubine was endowed with rights and protections by Hebrew law but was not equal in status to a wife'.

We know that both Abraham and Kind David had concubines. I am not aware of any OT scripture that explicitly condemns such behaviour.
Hi hi p
Genesis 25:6
But while he was still living, he gave gifts to the sons of his concubines and sent them away from his son Isaac to the land of the east.

2 Samuel 5:13
After he left Hebron, David took more concubines and wives in Jerusalem, and more sons and daughters were born to him.

Now when we come to the NT we have this from Paul:
1 Corinthians 6:9-10
Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.

Hey All,
"We know that both Abraham and Kind David had concubines. I am not aware of any OT scripture that explicitly condemns such behaviour." Quote from Wheat Field

It's in the first chapter of the Book.

Genesis 2:23-24 And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man.
Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.

Any coupling that is not mentioned, is not God ordained.
Because some men practiced polygamy didn't mean it was not a sin. It means they were in sin, and God loved them anyway.

Abraham may have the excuse as Genesis was not written in his lifetime. But anybody after Moses does not.

Romans 5:20
Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound:

Keep walking everybody.
May God bless,
Taz

 

[Wheat Field]

Yes, but my point was only that the first instance of polygamy in the Bible was by someone wicked. David came quite some time later.

Not necessarily. The normative for marriage, for sexual relations, is set out in Gen 2:24. That is held by Jesus and the Apostles, which means that is normative for Christians.

God let all sorts of sins slide, for a time. As with divorce, God allowed certain things because of the hardness of people’s hearts. As I pointed out, there is an explicit command for kings to not take multiple wives in Deut 17:17.

And it doesn’t mention the specific law that clearly shows David was in the wrong.

His polygamy set the pattern for taking any woman he wanted. By disregarding the Law, by breaking the command to not have multiple wives, it made it easier for David to then break the seventh and tenth commandments, which led to breaking the sixth. There is a clear pattern, imo.

Fair enough, but the biblical pattern for marriage approved by God is one man and one woman. There is no other acceptable marital or sexual relationship in Scripture. That the Bible describes certain other sexual relationships is neither implicit approval nor prescription of those things.

If the taking of multiple wives is a sin, then how is it possible that the Song of Solomon became part of the canon? Why would John Piper's ministry website say that it: '...poetically unfurls the glory of marriage and sex in a way that lauds complementarian monogamy'.

That is an unconscionable statement imho. How could they get it so wrong? (I looked for a contact address to ask as much but didn't find one). Am I missing something here?

It remains astonishing that there is no explicit law proscribing polygamy; rather there are laws that deal with the reality of it. The focus of Deuteronomy 17:17 is guarding against the king's heart being led astray rather than specifically against having more than one wife.

He must not take many wives, or his heart will be led astray. He must not accumulate large amounts of silver and gold.

I think the scriptures that most significantly address the polygamy issue are from Jesus - and you have mentioned both (though I would cite the Matthew 19:9 version rather than Mark which reinforces the idea that the man is still considered married.

Even so, it still has to be inferred.

 

[for_his_glory]

God's grand design was creating Adam and then Eve to be his helpmate. Polygamy started with the lineage of Cain as mans hearts harden towards God. In the OT the only command against polygamy was for kings who were to only have one wife, Deuteronomy 17:17. Many like Abraham, Jacob, David, and Solomon all had more than one wife and God never condemned them, but also never approved either, but by their choice it wasn't always a good thing as it caused a lot of conflict between the man and his wives and that of the order of children born to him. Moses gave instruction in the law about the order of heirs from these multiple marriages, Deuteronomy 21:15-17. In the NT there are scriptures that speak against polygamy like 1Timothy 3:2, 12; Titus 1:6. Paul speaks of only one wife in 1 Corinthians 7:1-16. Ephesians 5:25-33 a husband and wife are compared to that of Christ and His Church.

Genesis 2: 24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.

Scripture is silent on God allowing polygamy as His intention was always one man and one women being united in marriage. Polygamy originated with the son of Cain with his 4x Great grandson Lamech (Genesis. 4:16-19) Although several biblical characters such as Elkanah, Solomon and David were polygamists the Bible gives clear examples of the destructiveness of this practice. Polygamy resulted in much heartache and trouble (Gen. 16:1-6; 1 Sam. 1:2-8; 1 Kings 11:1-8). God forbid kings to multiply wives (Deut. 17:14,17). David, Solomon, and other kings who had multiple wives were living contrary to God's Word.

 

[Free]

If the taking of multiple wives is a sin, then how is it possible that the Song of Solomon became part of the canon? Why would John Piper's ministry website say that it: '...poetically unfurls the glory of marriage and sex in a way that lauds complementarian monogamy'.

That is an unconscionable statement imho. How could they get it so wrong? (I looked for a contact address to ask as much but didn't find one). Am I missing something here?

I think you may be misunderstanding the intent of that passage. It isn’t saying that the perfect one is in the royal harem or that the speaker even has a harem. Notice what Song of Solomon says in verse 8:

Sng 6:8 There are sixty queens and eighty concubines, and virgins without number. (ESV)

The number increases each time, not to mention that there is typically only one queen, never mind sixty. It is possibly comparing the “perfect one” with the women in royal harems, which I suspect were chosen for their beauty, but more likely comparing her to all women (“without number”). So, Piper is correct.

It remains astonishing that there is no explicit law proscribing polygamy; rather there are laws that deal with the reality of it.

How many things can you name off the top of your head for which there is no explicit law or command? Which of those can be guided by general principles found in Scripture? There are things in the OT which Scripture merely describes as a fact of life in ancient near-eastern cultures, without either prescribing any law or command against, or providing laws to regulate and change how things are done. For instance, releasing slaves in the year of jubilee.

The point is that God uses progressive revelation throughout the Bible to change his people’s hearts and not by massive change all at once.

The focus of Deuteronomy 17:17 is guarding against the king's heart being led astray rather than specifically against having more than one wife.

He must not take many wives, or his heart will be led astray. He must not accumulate large amounts of silver and gold.

Sure, but the point is that kings were not to have many wives, which clearly includes David. Yet, he was still said to have done “what was right in the eyes of the LORD and did not turn aside from anything that he commanded him all the days of his life, except in the matter of Uriah the Hittite” (1 Kings 15:5, ESV). That’s the argument I was addressing, so the reason for the command in Deut 17:7 doesn’t really matter.

I think the scriptures that most significantly address the polygamy issue are from Jesus - and you have mentioned both (though I would cite the Matthew 19:9 version rather than Mark which reinforces the idea that the man is still considered married.

Even so, it still has to be inferred.

But, what matters is what is stated in Gen 2:24, which both Jesus and Paul appeal to as being normative. That’s the general principle, but Jesus also provides some additional revelation and clarification, which is consistent with progressive revelation.