From
http://ldsfaq.BYU.edu/emmain.asp?number=145
Joseph Smith realized that the introduction of plural marriage would inevitably invite severe criticism. After the Kirtland experience, he knew the tension it would create in his own family; even though Emma, with faith in his prophetic calling, accepted the revelation as being from God and not of his own doing, she could not reconcile herself to the practice. Beyond that, it had the potential to divide the Church and increase hostilities from outside. Still, he felt obligated to move ahead. "The object with me is to obey & teach others to obey God in just what he tells us to do," he taught several months before his death. "It mattereth not whether the principle is popular or unpopular. I will always maintain a true principle even if I Stand alone in it" (TPJS, p. 332).
Although certain that God would require it of him and of the Church, Joseph Smith would not have introduced it when he did except for the conviction that God required it then. Several close confidants later said that he proceeded with plural marriage in Nauvoo only after both internal struggle and divine warning. Lorenzo Snow later remembered vividly a conversation in 1843 in which the Prophet described the battle he waged "in overcoming the repugnance of his feelings" regarding plural marriage.
"He knew the voice of God-he knew the commandment of the Almighty to him was to go forward-to set the example, and establish Celestial plural marriage. He knew that he had not only his own prejudices and pre-possessions to combat and to overcome, but those of the whole Christian world…; but God…had given the commandment" [The Biography and Family Record of Lorenzo Snow, pp. 69–70 (Salt Lake City, 1884)].
Even so, Snow and other confidants agreed that Joseph Smith proceeded in Nauvoo only after an angel declared that he must or his calling would be given to another (Bachman, pp. 74–75). After this, Joseph Smith told Brigham Young that he was determined to press ahead though it would cost him his life, for "it is the work of God, and He has revealed this principle, and it is not my business to control or dictate it" (Brigham Young Discourse, Oct. 8, 1866, Church Archives).
Nor did others enter into plural marriage blindly or simply because Joseph Smith had spoken, despite biblical precedents. Personal accounts document that most who entered plural marriage in Nauvoo faced a crisis of faith that was resolved only by personal spiritual witness. Those who participated generally did so only after they had obtained reassurance and saw it as religious duty.
Even those closest to Joseph Smith were challenged by the revelation. After first learning of plural marriage, Brigham Young said he felt to envy the corpse in a funeral cortege and "could hardly get over it for a long time" (JD 3:266). The Prophet´s brother Hyrum Smith stubbornly resisted the very possibility until circumstances forced him to go to the Lord for understanding. Both later taught the principle to others. Emma Smith vacillated, one day railing in opposition against it and the next giving her consent for Joseph to be sealed to another wife (see comments by Orson Pratt, JD 13:194).
Teaching new marriage and family arrangements where the principles could not be openly discussed compounded the problems. Those authorized to teach the doctrine stressed the strict covenants, obligations and responsibilities associated with it—the antithesis of license. But those who heard only rumors, or who chose to distort and abuse the teaching, often envisioned and sometimes practiced something quite different. One such was John C. Bennett, mayor of Nauvoo and adviser to Joseph Smith, who twisted the teaching to his own advantage. Capitalizing on rumors and lack of understanding among general Church membership, he taught a doctrine of "spiritual wifery." He and associates sought to have illicit sexual relationships with women by telling them that they were married "spiritually," even if they had never been married formally, and that the Prophet approved the arrangement. The Bennett scandal resulted in his excommunication and the disaffection of several others. Bennett then toured the country speaking against the Latter-day Saints and published a bitter anti-Mormon exposé charging the Saints with licentiousness.
The Bennett scandal elicited several public statements aimed at arming the Saints against the abuses. Two years later enemies and dissenters, some of whom had been associated with Bennett, published the Nauvoo Expositor, to expose, among other things, plural marriage, thus setting in motion events leading to Joseph Smith´s death (see Martyrdom of Joseph and Hyrum Smith).
Far from involving license, however, plural marriage was a carefully regulated and ordered system. Order, mutual agreements, regulation, and covenants were central to the practice. As Elder Parley P. Pratt wrote in 1845,
"These holy and sacred ordinances have nothing to do with whoredoms, unlawful connections, confusion or crime; but the very reverse. They have laws, limits, and bounds of the strictest kind, and none but the pure in heart, the strictly virtuous, or those who repent and become such, are worthy to partake of them. And…[a] dreadful weight of condemnation await those who pervert, or abuse them" [The Prophet, May 24, 1845; cf. D&C 132:7].
The Book of Mormon makes clear that, though the Lord will command men through his prophets to live the law of plural marriage at special times for his purposes, monogamy is the general standard (Jacob 2:28–30); unauthorized polygamy was and is viewed as adultery. Another safeguard was that authorized plural marriages could be performed only through the sealing power controlled by the presiding authority of the Church (D&C 132:19).