The term deprecated doctrines within Mormonism describes various doctrines that are not officially held or promoted at large within the Mormon religion today. Some were taught by past prophets, while others are still held by LDS although not considered "official" doctrine. Mormons often exclaim that by exposing these past beliefs that some are using "anti-Mormon" techniques to bring down the Mormon religion. However, Mormonism is full of quotes and pages of support for the beliefs below. Through the use of basic historical research it can be shown that these beliefs were in fact strongly held by early and pre-modern Mormons. The results such research will shed light upon what Mormons actually beleived and how they dealt with the dismissal of some of these beliefs.
Early Mormonism taught a form of modalism, as is evident in Joseph Smith's retranslation of the Bible, the Lectures on Faith, and the 1830 version of the Book of Mormon.
- "No clear distinction is made between the person of God the Father and the person of God the Son in the  Book of Mormon. In fact Jesus is clearly asserted to be both. No clear distinction is made between the person of God the Father and the person of God the Son in the Book of Mormon. In fact Jesus is clearly asserted to be both. This is stated most baldly in Ether 3:14: “I am Jesus Christ. I am the Father and the Son.” The Son is repeatedly referred to as the “Eternal Father.” (1 Nephi 11:21, 13:40; Mosiah 16:15; Alma 11:37-38). And so we read, for example, “behold the Lamb of God, yea, even the Eternal Father,” (1 Nephi 11:21), and “the Lamb of God is the Eternal Father and the Saviour of the world.” (1 Nephi 13:40; cf., Mosiah 16:15 and Alma 11:37-38)." 
- See main page: Modalism
 Lectures on Faith
Lectures on Faith (formerly "of Faith") have been removed from Mormon canon.
"[According to non-apologetic commentators], the Lectures represented official church doctrine in 1835, but that by 1897 or 1921 when the work was decanonized by the major Latter Day Saint denominations, the doctrine concerning the Godhead had changed, and were no longer generally consistent with the Lectures." 
- See main page: Lectures on Faith
- Lectures on Faith (Wikipedia)
 Individual blood atonement
"[A]ccording to this doctrine there are certain sins which place the sinner beyond the forgiving power of the blood of Christ. The only way the sinner can achieve forgiveness is to have his or her own blood shed." 
- "Man may commit certain grievous sins - according to his light and knowledge -that will place him beyond the reach of the atoning blood of Christ. If then he would be saved, he must make sacrifice of his own life to atone - so far as the power lies - for that sin, for the blood of Christ alone under certain circumstances will not avail. Joseph Smith taught that there were certain sins so grievous that man may commit, that they will place the transgressors beyond the power of the atonement of Christ. If these offenses are committed, then the blood of Christ will not cleanse them from their sins even though they repent" -Joseph Fielding Smith (Tenth Mormon prophet and president), Doctrines of Salvation, 1:135, 138
- See main page: Blood atonement
- Mormon Blood Atonement: Fact of Fantasy?, by Jerald & Sandra Tanner
- Mormonism and Blood Atonement (Saints Alive in Jesus)
- Blood Atonement - If It Was Never Taught, Why Do So Many Mormons Believe It?, by Bill McKeever
- Blood Atonement (Institute of Religious Research)
- Letter to Thomas B. McAfee from Bruce McConkie (Mormon)
 Practice of polygamy
Mormons of the mainstream sect no longer practice polygamy.
- The Four Major Periods of Mormon polygamy, by Todd M. Compton
- See main page: Adam-God theory
- Adam-God Doctrine (Institute for Religious Research)
- The Adam-God Doctrine and Living Prophets, by Jerald and Sandra Tanner
- "Adam-God" - Brigham Young's Theory or Divine Doctrine?, by Bill McKeever
 Former versions of temple ceremony
The Mormon "temple endowment" has gone through a series of changes, particularly dramatic ones as of 1990.
- The LDS Temple Ceremony, by Bill McKeever
- Background surrounding the 1990 changes to the Mormon temple ceremony
- Major changes made to Initiatory Ordinances starting on Tues. Jan. 18, 2005, by Michael Norton (scroll down some)
 Theological racism
- Mormonism's Racist Theology
- Residual Racism in Modern Mormonism, by Timothy Oliver
- Racism in Mormonism (Utah Lighthouse Ministry) - Various articles
 The law of adoption
"[E]arly Mormons sealed living men to other men in an unusual ceremony known as 'the law of adoption.' Thus a man could have any number of men adopted to himself as his sons for eternity." 
- Sealing Men to Men: An Early Mormon Doctrine, by Jerald & Sandra Tanner