HERESIES OF THE MORMONS
The Mormons base all their doctrine on what they call the sacred “Book of Mormon”, and their book of “Doctrines and Covenants”, in spite of the fact that the Word of God contained in the Bible is complete, and any new "revelation" is accursed (John 12:48, Galatians 1:8, 1 Thessalonians 2:13, Revelation 22:18-19).
The Book of Mormon was dictated, as they say, from behind a curtain, by an individual called Joseph Smith (illiterate and of bad reputation) firstly to Martin Harris and when Harris was tired, to Oliver Cowdery, all North American. Joseph Smith alleged that an angel had showed him where a number of gold plates covered in writings in an unknown language were buried, and had given him two crystals set in a silver bow, that he called Urim and Thummim, by which he could read in English what was written in them, and this was what he dictated. To complete the fraud, Smith declared that the “golden plates” were carried off, together with the spectacles, etc., by the angel as soon as he had dictated their contents, so no one but he ever saw them!
The book of the Doctrines and Alliances tells, among other things, of a new "revelation" that Joseph Smith said he received, justifying his polygamy.
Joseph Smith founded the "church" of Mormon, with himself as “seer, translator, prophet, apostle of Jesus Christ, and elder of the Church”. His end was tragic: once, with his accomplice Rigdon (a charlatan that began as a Baptist pastor) he had to flee precipitately to escape from the law because of their flotation of a bogus bank concern. After more frauds the chief of his own followers rose in revolt, determined to expose him. A free fight led to Smith and his brother being imprisoned, but an armed mob rushed the prison and both Smith and his brother were killed. Unfortunately that gave his followers the opportunity to weave around his name a halo of martyrdom, and Rigdon was excommunicated by his rival Brigham Young, who became the leader of Mormonism.
CORRUPTION OF THE BIBLICAL TEXT
The most repugnant "interpretations" are given by them to Biblical facts and doctrines (comp. II Timothy 3:16-17, II Peter 1:21, 2:1-3,10, 3:14-18). For instance, they teach that God is an exalted man, once a man on earth as we are now, ever changing and advancing, but never absolutely perfect. Joseph Smith said that “God the Father lived in the world, the same as Jesus Christ did”, and his successor Brigham Young, even more revered than he by their "church", explained that Adam is God, the supreme God. There is a lot more of this kind of teaching.
EXCLUSIVENESS
For them, who like to call themselves “church of latter-day saints”, all Christian churches are anathema (reversing what the Word of God calls its doctrine - compare with Luke 18:11, John 9:41, II Corinthians 10:12, Colossians 2:18-19; II Timothy 2:19, 3:1-9); they think of themselves as the only church of God, to which all nations owe submission. According to them, all churches teach false doctrine and are under the curse of God.
POLYGAMY
According to information given by people who knew Joseph Smith from his childhood, he not only was utterly destitute of conscience and a notorious liar, but also well known for his vulgar speech and his life of unspeakable lewdness. After escaping from the agents of the law who sought him because of his frauds, he settled out of their reach in the state of Illinois, and there he took for himself several "wives" (Comp. Malachi 2:15, Matthew 19:4, 1 Timothy 3:2, Titus 1:6).
After founding and leading his “church”, he justified his actions by a convenient "revelation", nauseating in its content. When he died, Brigham Young, who was called the “chief of the twelve apostles” excommunicated his accomplice Rigdon, and fled with the members of the "church" in 1847 for the state of Utah (at that time belonging to Mexico) to escape from the laws of the United States, which were contrary to polygamy and other practices of theirs.
They settled down in Salt Lake City, and Brigham Young died in 1877 leaving an immense fortune, 17 wives and 56 children and daughters. When Utah came to belong to the United States, they had to submit to their laws, but polygamy is still part of their doctrines, and many practice it, some secretly in countries where the laws don't allow it.
MYSTICISM
In Mormonism there are two elements which force their followers not to leave it, the first being mysticism (comp. 2 Timothy 4:4). Each Mormon dresses what they call a dotal robe, containing ciphers and symbols of things very important to him. He receives this robe after participating in secret ceremonies in their temple, and the Mormons don't dare to divulge the secrets that are taught there (John 3:19, Romans 13:12, Ephesians 5:12-13).
BAPTISM FOR THE DEAD
After mysticism this is the second element: one of their many false doctrines consists of saying that nobody can be saved if they are not baptized by them, and that the souls of the dead can "be freed" by a live person's baptism in their place (Comp. Hebrews 9:27)! Many of their doctrines, besides this, are only taught as the beginner is progressing in his discipleship, during which their mentors submit him to oaths and religious and material obligations from which he will find it difficult to escape.
It is a religious autocracy ruled by their priests who command not only the religious life but also the secular life of those who belong to it.