Book of Revelation
The Book of Revelation, also called Revelation to John or Apocalypse of John is the last canonical book of the New Testament in the Bible. It is the only biblical book that is wholly composed of apocalyptic literature.
After a short introduction (ch. 1:1–10), it contains an account of the author, who identifies himself as John, and of two visions that he received on the isle of Patmos. The first vision (chs. 1:11–3:22), related by "one like unto the Son of man, clothed with a garment down to the foot, and girt about the paps with a golden girdle", speaking with "a great voice, as of a trumpet," are statements addressed to the seven churches of Asia. The second vision comprising the rest of the book (chs. 4–22) begins with "a door … opened in heaven" and describes the end of the world—involving the final rebellion by Satan at Armageddon, God's final defeat of Satan, and the restoration of peace to the world.
Revelation is considered by many Christians as one of the most controversial and difficult books of the Bible, with many diverse interpretations of the meanings of the various names and events in the account. Protestant founder Martin Luther at first considered Revelation to be "neither apostolic nor prophetic" and stated that "Christ is neither taught nor known in it" . However, he later changed his mind. John Calvin believed the book to be canonical, yet it was the only New Testament book he did not write a commentary on.
In the 4th century, St. John Chrysostom and other bishops argued against including this book in the New Testament canon, chiefly because of the difficulties of interpreting it and the danger for abuse. Christians in Syria also reject it because of the Montanists' heavy reliance on it. In the 9th century, it was included with the Apocalypse of Peter among "disputed" books in the Stichometry of St. Nicephorus, Patriarch of Constantinople. In the end it was included in the accepted canon, although it remains the only book of the New Testament that is not read within the Divine Liturgy of the Eastern Orthodox Church.
In contrast with these and other Christian leaders and theologians, the prophet Joseph Smith said that "The Book of Revelation is one of the plainest books God ever caused to be written". He invited members of the Church to seek the Holy Spirit to understand the important messages of this book for their lives.
The messages contained in the Book of Revelation are taught in The Church of Jesus Christ of Latter-day Saints' Gospel Doctrine classes in Sunday School as part of the New Testament study year. The manual states, 
- John was one of the Savior’s original Apostles. He had been banished by the Roman government to Patmos, a small island off the west coast of present-day Turkey, for bearing testimony of Jesus Christ. While there, John was visited by an angel and given a revelation that he recorded in letters to the seven branches of the Church in Asia (Revelation 1:1, 9–11). These letters became the book of Revelation.
- The book of Revelation is written primarily in symbolic language. Its theme is that “there will be an eventual triumph on this earth of God over the devil; a permanent victory of good over evil, of the saints over their persecutors, of the kingdom of God over the kingdoms of men and of Satan. … The details about the beasts, the wars, the angels, the men, etc., contribute to the development of this theme. By a little study, the theme can be perceived even if the details are not completely identified” (Bible Dictionary, “Revelation of John,” 762).
Regarding Revelation, chapter 12, LDS prophet Wilford Woodruff said,
- There are two powers on the earth and in the midst of the inhabitants of the earth—the power of God and the power of the devil. … When God has had a people on the earth, it matters not in what age, Lucifer, the son of the morning, and the millions of fallen spirits that were cast out of heaven, have warred against God, against Christ, against the work of God, and against the people of God. And they are not backward in doing it in our day and generation. Whenever the Lord set His hand to perform any work, those powers labored to overthrow it. 
Latter-day Saints are often accused of adding scripture, when the Book of Revelation so obviously reviles against that possibility. Christians outside the Mormon Church often quote the following scriptures to condemn LDS doctrine and open scripture:
- “For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
- “And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book” (Revelation 22:18–19).
- Let us first consider what John meant by “this book” and then consider what he meant by not adding to or taking from it. When John wrote the Book of Revelation in the latter part of the first century a.d., he was not writing the concluding pages of the New Testament, as there was no New Testament in existence at that time. He was an exile on the isle of Patmos and was writing a scroll addressed to seven branches of the Church on the western side of what we today call Turkey. His manuscript was entirely independent of the rest of the 27 separate manuscripts that later came to form the anthology that we know of as the New Testament. Nor was his manuscript necessarily the last one written. It is the consensus of those who have written on the subject that several of these 27 scrolls were written after the Book of Revelation was written. Not until the fourth century a.d. did the emerging collection of sacred writings become the New Testament essentially as we know it today. In the light of these facts, we may see that when John spoke of “this book,” he wasn’t referring to a not-yet-formed New Testament but simply to his own scroll, the Book of Revelation itself.
- What, then, does John mean when he commands anyone who reads his work not to add words to it or to take words from it? He means that no one should tamper with the text of his scroll in any way. He wants no copyist, no would-be deceiver, no well-intentioned but misguided believer, no one to make any changes in the way it reads. He wants it to remain precisely as he has inscribed it under the inspiration of the Lord. It is interesting that the author of Deuteronomy, the fourth book of the Old Testament, similarly warns his readers, “Ye shall not add unto the word which I command you, neither shall ye diminish aught from it.” (Deuteronomy 4:2; compare Deuteronomy 12:32.) In both cases the writers are commanding future viewers of their sacred manuscripts not to alter anything that has been written. Fortunately, no one seems to be arguing, on the basis of the injunction in Deuteronomy, that there never was to be any more scripture, for then some people might conclude that the rest of the Bible must be rejected.
- Not only is John not saying that there never would be additional scripture, but the inevitable conclusion that one must draw from the Book of Revelation, when taken as a whole, is that John recognized that there undoubtedly would be additional scripture in the last days. How so? What is scripture (Latin: scriptura, “a writing”) but divine revelation in written form? A good portion of the Book of Revelation is a prophecy of heavenly messengers coming to earth at a time beyond John’s day. When such messengers come and a written record is made of the visit and their message, automatically new scripture is formed. In the 11th chapter of the Book of Revelation John predicts the mission of two prophets who will prophesy in Jerusalem at the time of the end. When they prophesy and their divinely revealed message from God is preserved in a written record, again new scripture will be formed. Rising above all other events in prophetic significance in the Book of Revelation is the predicted second coming of Jesus Christ. When Christ comes and men of God make a written record of his coming, once more new scripture will be formed.
- Rather than the Book of Revelation teaching us that there was never to be more scripture given to the human family, the little volume, viewed from beginning to end, becomes splendid evidence that there would be and must be additional scripture in the last days. 
- Lesson 45: “He That Overcometh Shall Inherit All Things”, New Testament Gospel Doctrine Teacher’s Manual, 186.
- Deseret Evening News, 17 Oct. 1896, 9; quoted by Gordon B. Hinckley, in Conference Report, Oct. 1986, 56; or Ensign, Nov. 1986, 43.
- Eldin Ricks, “Q&A: Questions and Answers:How do we explain Revelation 22:18 that says not to add to the scriptures?” New Era, Sept. 1977, 44.