Revelations 14

Of his revelation, John wrote during the sixth seal -

"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,
7 Saying with a loud voice, Fear God, and give glory to him; for the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters." (New Testament Revelation 14:6 - 7)

What was this "everlasting gospel"? In modern day revelation we learn that -

"Behold, this is wisdom in me; wherefore, marvel not, for the hour cometh that I will drink of the fruit of the vine with you on the earth, and with Moroni, whom I have sent unto you to reveal the Book of Mormon, containing the fulness of my everlasting gospel, to whom I have committed the keys of the record of the stick of Ephraim..." (Doctrine and Covenants Section 27:5)

Ezekiel talked of two sticks when the Lord instructed him -

"Moreover, thou son of man, take thee one stick, and write upon it, For Judah, and for the children of Israel his companions: then take another stick, and write upon it, For Joseph, the stick of Ephraim, and for all the house of Israel his companions:
17 And join them one to another into one stick; and they shall become one in thine hand." (Old Testament Ezekiel 37:16 - 17)

Both sticks testifying that Jesus is the Christ. As a result of the keys of the record Ephraim held by this angel, the Prophet Joseph Smith -

"...has brought forth the Book of Mormon, which he translated by the gift and power of God, and has been the means of publishing it on two continents; has sent the fulness of the everlasting gospel, which it contained, to the four quarters of the earth..." (Doctrine and Covenants Section 135:3)

We not only learn by modern revelation that the angel John saw may have not only been Moroni, but others -

"And also with Elias, to whom I have committed the keys of bringing to pass the restoration of all things spoken by the mouth of all the holy prophets since the world began, concerning the last days;
7 And also John the son of Zacharias, which Zacharias he (Elias) visited and gave promise that he should have a son, and his name should be John, and he should be filled with the spirit of Elias;
8 Which John I have sent unto you, my servants, Joseph Smith, Jun., and Oliver Cowdery, to ordain you unto the first priesthood which you have received, that you might be called and ordained even as Aaron;
9 And also Elijah, unto whom I have committed the keys of the power of turning the hearts of the fathers to the children, and the hearts of the children to the fathers, that the whole earth may not be smitten with a curse;
10 And also with Joseph and Jacob, and Isaac, and Abraham, your fathers, by whom the promises remain;
11 And also with Michael, or Adam, the father of all, the prince of all, the ancient of days;
12 And also with Peter, and James, and John, whom I have sent unto you, by whom I have ordained you and confirmed you to be apostles, and especial witnesses of my name, and bear the keys of your ministry and of the same things which I revealed unto them;
13 Unto whom I have committed the keys of my kingdom, and a dispensation of the gospel for the last times; and for the fulness of times, in the which I will gather together in one all things, both which are in heaven, and which are on earth;
14 And also with all those whom my Father hath given me out of the world." (Doctrine and Covenants Section 27:6 - 14)

Of these, Elder Bruce R. McConkie taught -

“Now, as to the actual work of restoration—what angel performed this mighty deed, this work which involves the salvation of all men on earth in these latter-days? Who restored the everlasting gospel? Was it one angel or many?

It is traditional (and true!) to reply: ‘Moroni, son of Mormon, the now resurrected Nephite prophet, who holds the keys of “the stick of Ephraim”, the one through whose ministry the Book of Mormon was again brought to light.’ The reasoning that the Book of Mormon contains ‘the fulness of the everlasting gospel’; that therein is God’s message of salvation for all of the earth’s inhabitants; and that this gospel message is now being taken by the Lord’s witnesses to one nation, and kindred, and tongue, and people after another. . . .

. . . But other angels were yet to come—Moses, Elias, Elijah, Gabriel, Raphael, and ‘divers angels. . . . all declaring their dispensation, their rights, their keys, their honors, their majesty and glory, and the power of their priesthood; giving line upon line, precept upon precept; here a little, and there a little.’

Thus the angel Moroni brought the message, that is, the word; but other angels brought the keys and priesthood, the power. And in the final analysis the fulness of the everlasting gospel consists of all of the truths and powers needed to enable men to gain a fulness of salvation in the celestial heaven.” (McConkie, DNTC, 3:528–30.)

So much is revealed in just a few verses.