Please note that while critics often claim the Book of Mormon condemns plural marriage, a careful reading of the text shows that this interpretation is incorrect. The Lord condemns plural marriage when the practice is used to gratify lustful desires for sensuality. Such perversion of a sacred doctrine violates the Lord's standards on sexuality. However, at times a divine commandment is given to "raise up seed unto" God. In such cases, the practice is not only approved, but the necessary prerequisites (e.g., patience, love, humility) leads the practitioners into deeper sanctification.
No, in the Old Testament God condemned polygamy primarily because it would lead people astray. Lust and sensuality had nothing to do with it. Can anyone have sex in an un-sensual way? (Thinking of England, for example?) Even if "the Lord approved", sensuality and lust are still there. Somehow, "holy sex" leads to "sanctification", according to Walsh. God's "yea" makes it holy. This is another urban myth from people who think that polygamy can in fact be practised "in purity". When was it ever practised "in purity"? It was a disaster in the Old Testament, and it was a disaster in 19th century Mormonism, for the most part, in my opinion, and nearly destroyed the Church. Today the Church has all but publicly disowned it.
Do you ever see official qualifications to the media that "we still believe it in principle". Let me know, because I've never found it. Did GBH ever say to interviewers "it was a holy practice", and "participated in with right intent and with the Lord's approval it is sanctifying". No, he said "it's behind us".
The early Brigham Young:
"Some of these my brethern know what my feelings were at the time Joseph revealed the doctrine; I was not desirous of shrinking from any duty, nor of failing in the least to do as I was commanded, but it was the first time in my life that I had desired the grave, and I could hardly get over it for a long time. And when I saw a funeral, I felt to envy the corpse its situation, and to regret that I was not in the coffin, knowing the toil and labor that my body would have to undergo; and I have had to examine myself, from that day to this, and watch my faith, and carefully meditate, lest I should be found desiring the grave more than I ought to do."
The later Brigham Young:
"Brother Cannon remarked that people wondered how many wives and children I had. He may inform them, that I shall have wives and children by the million, and glory, and riches and power and dominion, and kingdom after kingdom, and reign triumphantly,"
Brigham Young, Journal of Discourses, vol. 8, p. 178.
Years after this statement, his interview with Horace Greeley:
Horace Greeley: How general is polygamy among you?
Brigham Young: I could not say. Some of those present (heads of the church) have each but one wife; others have more; each determines what is his individual duty.
Horace Greeley: What is the largest number of wives belonging to any one man.
Brigham Young: I have fifteen; I know no one who has more; but some of those sealed to me are old ladies whom I regard rather as mothers than wives, but whom I have taken home to cherish and support.
This is what defending polygamy does to people. Why? Because it is indefensible, and everyone knows it.