I disagree strongly with the way Mormon polygamy was practiced. I disagree strongly that a god would command and threaten to kill people if they didn't go outside their marriage to get sex without the permission of their spouse. I disagree with a man being able to shag whomever he can while the woman cannot enjoy the same privilege.
God seems to condone it here:
And I gave thee thy master's house, and thy master's wives into thy bosom, and gave thee the house of Israel and of Judah; and if that had been too little, I would moreover have given unto thee such and such things."
2 Samuel 12:8.
So if his hundreds of wives weren't enough, he would have given him many more. that's the difference between polig and slaves. The Bible makes allowances for a cultural norm slavery, but does not cast it in a positive or negative light. This verse seems to say these wives were a "good" thing, because God doesn't do evil. So the least you can say (or someone that believed about the Bible) is it's not evil.
I'll be honest, I don't really think polygamy is that great of an idea. Just pointing out, it's well defended in the Bible. What is not defended is Joseph Smiths kind of Polygamy.. he would be just as guilty as david for stealing other mens wives.
..must make sacrifice of his own life to atone. for the blood of Christ alone under certain circumstances will not avail." - Bruce R. McConkie
And so I tell you, every sin and blasphemy will be forgiven, … Anyone who speaks a word against the Son of Man (a.k.a., Jesus) will be forgiven (Matthew 12:31-32).