The Apostle John was also known as John the Revelator. Unlike all the other Apostles, he was not killed. We learn in latter-day scripture that the Savior asked him: “John, my beloved, what desirest thou? For if you shall ask what you will, it shall be granted unto you.
“And [John] said unto him: Lord, give unto me power over death, that I may live and bring souls unto thee.
“And the Lord said unto [John]: Verily, … because thou desirest this thou shalt tarry until I come in my glory [His Second Coming]” (D&C 7:1–3).
Although he was not killed, he was exiled (forced to live away from his country) on the Isle of Patmos. It was there that he wrote the last book of the Bible, Revelation. Many believe it to be the hardest book of scripture to understand. However, the Bible Dictionary explains that the “message of Revelation is the same as that of all scripture: there will be an eventual triumph on this earth of God over the devil; a permanent victory of good over evil, … of the kingdom of God over the kingdoms of men and of Satan” (Bible Dictionary—Revelation of John).
In Revelation, John talked much about what would happen before and during the Second Coming of Jesus Christ. One vision he described was this: “And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people” (Rev. 14:6).
A fulfillment of this prophecy came when the angel Moroni appeared to the Prophet Joseph Smith and told him of the Book of Mormon, which contains the “fulness of the gospel of Jesus Christ to the Gentiles and to the Jews also” (D&C 20:9). Gentiles, here, means anyone who is not a Jew. In other words, with the publishing of the Book of Mormon and the restoration of the Savior’s Church, the gospel was to be taught to all people everywhere. Those who teach the gospel are called witnesses of God, or missionaries.
All young men—and young women who wish to—should prepare to go on a full-time mission. Older people are asked to go on missions, too, if they can. Missionary work is very important and must be done before the Second Coming of the Savior. President David O. McKay (1873–1970) said that all members—that includes children—of The Church of Jesus Christ of Latter-day Saints should be missionaries by example and by sharing the gospel to anyone who is sincerely interested in it. All of us must be witnesses of God.