Church Newsroom Statement on polygamy and polygyny.
"Polygamy: Latter-day Saints and the Practice of Plural Marriage," LDS Church Newsroom; accessed September 28, 2021
Polygamy — or more correctly polygyny, the marriage of more than one woman to the same man — was an important part of the teachings of The Church of Jesus Christ of Latter-day Saints for a half-century. The practice began during the lifetime of Joseph Smith but became publicly and widely known during the time of Brigham Young. Today, the practice of polygamy is strictly prohibited in the Church, as it has been for over 120 years.
In 1831, Church founder Joseph Smith made a prayerful inquiry about the ancient Old Testament practice of plural marriage. This resulted in the divine instruction to reinstitute the practice as a religious principle.
Latter-day Saint converts in the 19th century had been raised in traditional, monogamous homes and struggled with the idea of a man having more than one wife. It was as foreign to them as it would be to most families today in the western world. Even Brigham Young, who was later to have many wives and children, confessed to his initial dread of the principle of plural marriage.
Subsequently, in 1890, President Wilford Woodruff, fourth president of the Church, received what Latter-day Saints believe to be a revelation in which God withdrew the command to practice plural marriage. He issued what has come to be known as the "Manifesto," a written declaration to Church members and the public at large that stopped the practice of plural marriage.
Later, describing the reasons for the Manifesto, President Woodruff told Church members, "The Lord showed me by vision and revelation exactly what would take place if we did not stop this practice. If we had not stopped it, you would have had no use for ... any of the men in this temple ... for all (temple sacraments) would be stopped throughout the land. ... Confusion would reign ... and many men would be made prisoners. This trouble would have come upon the whole Church, and we should have been compelled to stop the practice."
Today Church members honor and respect the sacrifices made by those who practiced polygamy in the early days of the Church. However, the practice is outlawed in the Church, and no person can practice plural marriage and remain a member.
The standard doctrine of the Church is monogamy, as it always has been, as indicated in the Book of Mormon (Jacob chapter 2): “Wherefore, my brethren, hear me, and hearken to the word of the Lord: For there shall not any man among you have save it be one wife; and concubines he shall have none. … For if I will, saith the Lord of Hosts, raise up seed unto me, I will command my people; otherwise they shall hearken unto these things.”
In other words, the standard of the Lord’s people is monogamy unless the Lord reveals otherwise. Latter-day Saints believe the season the Church practiced polygamy was one of these exceptions.
Polygamous groups and individuals in and around Utah often cause confusion for casual observers and for visiting news media. The polygamists and polygamist organizations in parts of the western United States and Canada have no affiliation whatsoever with The Church of Jesus Christ of Latter-day Saints, despite the fact that the term "Mormon" — widely understood to be a nickname for Latter-day Saints — is sometimes misleadingly applied to them.
President Gordon B. Hinckley stated the following about polygamy in the Church's October 1998 general conference:“I wish to state categorically that this Church has nothing whatever to do with those practicing polygamy. They are not members of this Church. Most of them have never been members. They are in violation of the civil law. They know they are in violation of the law. They are subject to its penalties. The Church, of course, has no jurisdiction whatever in this matter.
"If any of our members are found to be practicing plural marriage, they are excommunicated, the most serious penalty the Church can impose. Not only are those so involved in direct violation of the civil law, they are in violation of the law of this Church. An article of our faith is binding upon us. It states, 'We believe in being subject to kings, presidents, rulers, and magistrates, in obeying, honoring, and sustaining the law' (Articles of Faith 1:12).”