Polygamy is definitely one of those things on my priority list to ask God about someday when we are able to get concise answers to our questions.
I've heard it argued many a time that it was allowed because men such as David were allowed to do so. But we're also given the example of the Pharisees asking Jesus why divorce had been allowed, and Jesus said, "Because your hearts were hard." He then goes on to say that divorce was never something God had intended.
It's always cited that God made a male and female and instituted marriage (therefore, marriage is heterosexual.) Likewise, God made one woman out of Adam's rib, not 10. But those are just my beliefs and I want to stress that I know I could be wrong. I'm waiting for God to tell me someday in person.
I personally believe that there are certain things, such as polygamy, that came to be accepted as a cultural norm but was not what God intended nor did He approve of it, but knew that people's hearts were hard and would refuse to give it up, so He gave laws concerning such things (rations for wives had to be equal, etc.)
In school, they called it something like "God's permissive laws" in which God didn't want it that way, but He knew humans had made up their minds and wouldn't change, so He made rules trying to prevent further abuse. I personally feel that slavery is part of that category too.
I remember reading Exodus 21:20-21: "Anyone who beats their male or female slave with a rod must be punished if the slave dies as a direct result, but they are not to be punished if the slave recovers after a day or two, since the slave is their property."
I first read this when I was a kid in grade school and I remember being utterly horrified, thinking, "What kind of God are we being taught to believe in, that He would allow people to be seen as property and beaten so badly that it takes them days to recover?"
Now again, this is just me, and I could be wrong, and some of the things I was taught could be wrong as well, but I don't believe God ever intended or approved of slavery, or for people to be seen as property. But humans insisted on doing this to each other, and for whatever reason, it was allowed and He went on to make rules about it.
But just because something is happening and is culturally accepted doesn't mean it's right or approved by God at all, as we have seen numerous times throughout the Bible.
I am not in any way saying that my beliefs are somehow absolute. I could be dead wrong about everything. But these are issues that I first read about as a young child and have had a troubled heart over them ever since.
Well said on the issues of polygamy and slavery. The Bible says we're each know in part. I might know nothing about something you know everything about, etc.
When it regards polygamy and slavery, it's pretty easy for me to see that as you said, polygamy was something God conceded to (
exactly like divorce) because people were bent on doing it. It was never His will or plan and never will be. And slavery was never God's will or plan. The very concept is about as anti-God as one can get since God made man with freewill despite the fact that his freewill could potentially harm him. Slavery negates freewill, if not in practice then by implication. Furthermore, there are other places in the OT where God condemns slavery and oppression.
The Bible doesn't mention every single thing, so we sometimes have to pay attention to our own
conscience on those matters. For example, the Bible never openly condemns pedophilia. Not even in Deuteronomy 27 where many other acts and sexual acts are condemned is pedophilia condemned. When this is the case and there's no clear word, God wants people to use their
conscience (not to be mistaken with your
instinct nor with your
intuition-- all three distinct and different from each other) which acts as a sort of resident 'voice of the Holy Spirit' in all people, christian and non.
Your conscience's job is solely to tell you not what is right (never what is right) but only and solely
what is wrong.
When it regards sex in Heaven (at least between married couples), I have this sense of
intuition that God will not 'take it away'. It's related to the same side of my intuition that tells me that God is
genuinely a good Person even when I'm not feeling or seeing it in my life or in others' lives. Sex is the only thing that belongs only to a couple and no one else. Though God owns and is before the partner for each spouse, He leaves the marriage bed all alone but owns everything else. It's hard to see Him saying, "Welp. You guys won't need your special thing anymore since you're now getting super upgraded." And I'm not an apologist for sex in Heaven. I think about things sometimes and though I can't fathom how one could have sex in Heaven what's harder for me to fathom is God taking away sex. Like a child, the simple and unbiased question to God taking away sex in Heaven is... "Why?"
Lastly, you said something about Matt. 22:30. It's very true that I'm the Bible Jesus often used figures of speech and could appear to be saying one thing when He doesn't at all mean it like He said it. A very good example of this is John 6 when Jesus told the people they must eat His flesh and drink His blood. Understandably, they were upset and ran off. But though that was what He said,
it wasn't at all what He meant. I believe that this was the way He was speaking to the Sadducees in Matt. 22:30. I believe there's a hidden hint to this in what He told them here:
"You are in error, not knowing the Scriptures or the power of God." Why would Jesus say they didn't know the Scriptures if the Scriptures said nothing about the topic they were asking about? Exactly. It would not surprise me even a little bit, because God talks in a veiled way like this throughout the entire Bible, if not only will there be sex in Heaven but there will be marriages too and maybe even childbirths. I wouldn't encourage anyone to run with this or think too long on it. But looking at God's character (eg. integrity or immutability), God's values (eg. family and community), and God's goodness (eg. giving us things we desire just because we desire them, even if those things are imperfect), it's hard for me to arrive at conclusions that don't seem to square with God's foundational character traits. The Canaanite woman also held fast to Jesus's foundational character (which, as she saw with eyes of faith, was over or more important (primary or first in importance) than His mission to the Jews). She saw past the disagreeable way Jesus seemed to be with her, and as a result Jesus praised her ability to see past the surface things and into His heart, and so she received the miracle she came to Him for. (Read the fascinating story in Matt. 15:21-28.)
It really is a joy to doggedly ask God "Why" (about anything and everything), like a little child asking His dad relentless questions,
until He unfolds hidden mysteries to you. My practice is that if something doesn't make sense or add up to me or if I disagree with something (in everyday life or in spirituality), I'll keep asking God until He tells me (unless I get too tired to keep asking).