Speaking against Polygamy brings Damnation

Journal of Discourses 5:204; “The principle of plurality of wives never will be done away” (Deseret News, November 7, 1855.) Kimball also said, “You might as well deny Mormonism and turn away from it, as to oppose the plurality of wives. Let the Presidency of this Church, and the Twelve Apostles, and all the authorities unite and say with one voice that they will oppose that doctrine, and the whole of them will be damned”. – Heber C. Kimball, Salt Lake City, October 12, 1856

At the time Kimball made this announcement he was an apostle.  His grandson Spencer W. Kimball became the twelfth prophet of the Church. 

Heber C. Kimball shared his wife Vilate with Joseph Smith and even gave his 14 year old daughter to Smith as a wife.  His most famous quote; “I think no more of taking another wife than I do of buying a cow”.