I concede that issues such as having multiple wives (Old Testament) versus the one man + one woman Christian law principle could be construed as morally different, however, there was a good reason for that difference (see above).
Um, we don't have to look beyond the Bible to figure out why God changed his mind. Matthew and Mark both have Jesus telling us that it was because of man's hard hearts (stubborness?) that He allows multiple wives. That makes him rather, er, human I guess. But we don't have to insinuate some greater good that was being fulifilled beyond Jesus own words, indeed if we limit our discussion to what's revealed in the Bible, we can't. And this does indeed make God look rather waffle-ish. "Don't make me stop this car! I MEAN IT NOW!"
And why would I ask fundamentalist Mormons on the EFFECTS of polygamy? We're talking Biblical morality, not how some groups feel about it.
Biblically, polygamy is fine.
"Now the overseer must be above reproach, the husband of but one wife, temperate, self-controlled, respectable, hospitable, able to teach," -1 Timothy 3:2
BA- By extension, to be "above reproach", any man would do so.
You imply that the conditions following "be above reproach" are merely examples and extensions of being above reproach. I wouldn't agree. How is being "able to teach" a reflection of being "above reproach"? Isn't it simpler, and therefore preferable, and plainer to see a bulleted list for overseers: be above reproach, AND have one wife, AND be temperate...
Besides, the point of the text is to show a DIFFERENCE IN STANDARDS. If we are all expected to meet the standards ot an overseer, then there is no need to have standards for an overseer. The scripture would be moot. It's much like the JW practice of expecting all to preach, though not all are commanded to preach. If no difference is needed, then the scripture is useless here.
It's clear on the face of it: overseers can have only one wife. Biblically. For others? We can either say the NT is mute (but implies endorsement, showing that the rank and file are exempt) or we can say the OT view has never changed. That would at least make God unchanging.
Looking at these things through modern spectacles, it is hard to see things as they were. Apparently the human genome allowed close mating back then without defects. Even in our day, most states allow first cousins to marry, and there are remarkably few defects as a result. Most domesticated animals are still "line-bred".
What I hear you saying then is that there is nothing wrong with having sex with your parents. As a Biblical morality. To remind you, the point is not genetics and birth defects, it's what is Biblically moral. The "cousins" argument is just red herring, we're not talking about cousins and we're not talking about the vaibility of progeny. And we're not talking about animal husbandry. I hear your support for descendents to have sex with their parents as an unchanging Biblically based moral.
Unless you are proposing that genetics is the arbiter of Biblical morality? Is that in the Bible?
That is why God gave the nation of Israel the Ten Commandments, as well as other guidelines, laws and principles in the Mosaic Covenant. God does not decide differently each day, He remains unchanged.
Then why did Jesus need to fulfill and REPLACE the law? That rather leaves the entire debate to a brief sentence: Love God, and love your neighbor as yourself. That then becomes the entire Biblical morality. Move along folks, no more to see here.
Abraham was tested to see how much faith he would put in God. If Abraham obeyed God, God knew He would spare Isaac’s life, if Abraham disobeyed God, Isaac’s life would have been spared. Either way, Isaac’s life was spared.
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Either way, Isaac would have lived, as he did.
Considering this reasoning of God's is not covered in the Bible, I think I would have to reject it as speculation at best, revisionist at worst (just as we would have to go out on a fishing expedition to determine God's problem with Cain's sacrifice). The simple narrative of the Bible gives us Abraham starting the sacrifice of his son (morally acceptable) and God stops him, but the "what if" scenarios ain't there. Biblically.
different times, different place = same morals, different perspective
What I hear is a variation on the difficulty of interpretation. It's another way of saying we cannot know the morals of the Bible because we will always interpret them from a current perspective. Which just means there are no empirical, objective morals obtainable from the Bible, just different ways to read the words.