Is the practice of polygamy required today?
Throughout religious history polygamy has been commanded, permitted, or not permitted by God according to “the circumstances, responsibilities, and personal… duties of the people of God” in their respective ages.
When Joseph Smith first learned in the early 1830s that polygamy as practiced by Old Testament patriarchs had been acceptable to God, he was still not permitted to enter into it. However, within a few years he and other Church members were permitted, but it was not then required of all Latter-day Saints. In 1852 the principle was taught publicly and for 38 years plural marriage was considered a commandment. The 1890 Manifesto removed the commandment, but history shows that polygamy was still permitted until 1904. Thereafter, plural marriage was (and is) not permitted. These directives have all been administered through the “one” man who holds the keys of sealing authority in an orderly way (D&C 132:8, 18).
In 1891, First Presidency Counselor George Q. Cannon explained: “The Nephites [in the Book of Mormon], according to all that has come down to us, were monogamists. This law was not given to them, as far as we have any account. Yet they were a great and a mighty people before the Lord.” To Jacob in the Book of Mormon, God stated that, depending upon His will and earthly circumstances, “I will command my people” (see Jacob 2:27-30) regarding their marriages practices, usually specifying monogamy, but at other times permitting or commanding polygamy.
Twice in section 132 God emphasizes that His house is a “house of order” (D&C 132:8, 18), suggesting that order is important in establishing the validity of an eternal marriage. The Prophet plainly instructed: “All the ordinances, systems, and administrations on the earth are of no use to the children of men, unless they are ordained and authorized of God; for nothing will save a man but a legal administrator; for none others will be acknowledged either by God or angels.”
God’s order is maintained through “one” man who holds priesthood keys that must be accessed to make any eternal marriage valid (D&C 132:18). The opinions and desires of other men and women are of no consequence. Sincerity cannot circumvent the need for this authority. Church members today believe the Church President is the “one” holding the sealing authority and he has taught that plural marriage is not permitted.
See also: Is Polygamy Required for Exaltation?
 Joseph F. Smith, July 7, 1878, Journal of Discourses, 20:28-29.
 According to Orson Pratt speaking in 1869, Joseph Smith “told individuals, then in the Church that he had inquired of the Lord concerning the principles of plurality of wives, and he received for answer that the principle of taking more wives than one is a true principle, but the time had not yet come for it to be practiced.” (Orson Pratt, October 7, 1869, Journal of Discourses, 13:193.)
 George Q. Cannon, November 1, 1891, in Stuy, Collected Discourses, 2:294. See also Orson Pratt, July 4, 1859, and October 7, 1869, Journal of Discourses, 6:351 and 13:192; H. W. Naisbitt, March 8, 1885, Journal of Discourses, 26:115.
 Brian C. Hales, Modern Polygamy and Mormon Fundamentalism: the Generations after the Manifesto, Salt Lake City: Greg Kofford Books, 2006, 77-96.
 Joseph Fielding Smith, comp. and ed. Teachings of the Prophet Joseph Smith 1938; Salt Lake City: Deseret Book, 1976 printing, 274.