At the end of his time with the Israelites, Moses prophesies that they will turn astray. He also says this:
15 ¶The Lord thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken;
Many mistakenly conclude that this Prophet is Christ, whose coming is detailed in the New Testament. It is very important to read verses like this in context. This is what the rest of the relevant verses say:
16 According to all that thou desiredst of the Lord thy God in Horeb in the day of the assembly, saying, Let me not hear again the voice of the Lord my God, neither let me see this great fire any more, that I die not.
17 And the Lord said unto me, They have well spoken that which they have spoken.
18 I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him.
19 And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him. (Deut. 18)
What is the purpose of this prophet? The purpose is to bring the Israelites--who originally rejected the invitation to come into the presence of God--into the presence of God. Through this prophet, the Lord will once again offer a covenant to the Israelites.
The offering of a covenant is a misunderstood topic. It is the key to understanding why the God of the Old Testament seems so fierce compared to the Jesus of the New Testament. The penalties for breaking the covenant given through Moses were severe and immediate. Modern Christians think this was a relic of the past. They don't read their Bible. In Acts, we see the resumption of stiff penalties for breaking the covenant when a couple is put to death because they hold back their goods when taught that they should have all things in common. The four gospels do not occur during the offering of a covenant. Acts does. The Old Testament does. When the covenant is resumed in our day, penalties will also resume. This is yet another reason why we should take caution in our tendency to wish God would build Zion. The main concern is not actually that you would be denied entrance. The main concern is that you would be given entrance, only to fail to keep God's commandments perfectly, at which time you may likely be killed.
But who is this fellow, and why such stiff penalties for not hearkening to his words (Deut 18:19)?
Jesus provides a lot more information about him in 3 Nephi 21.
1 And verily I say unto you, I give unto you a sign, that ye may know the time when these things shall be about to take place—that I shall gather in, from their long dispersion, my people, O house of Israel, and shall establish again among them my Zion;This fellow is widely described in scripture. His titles include "the one mighty and strong" and "root of Jesse" and "descendant of David" and "ensign to the people".
2 And behold, this is the thing which I will give unto you for a sign—for verily I say unto you that when these things which I declare unto you, and which I shall declare unto you hereafter of myself, and by the power of the Holy Ghost which shall be given unto you of the Father, shall be made known unto the Gentiles that they may know concerning this people who are a remnant of the house of Jacob, and concerning this my people who shall be scattered by them;
3 Verily, verily, I say unto you, when these things shall be made known unto them of the Father, and shall come forth of the Father, from them unto you;
4 For it is wisdom in the Father that they should be established in this land, and be set up as a free people by the power of the Father, that these things might come forth from them unto a remnant of your seed, that the covenant of the Father may be fulfilled which he hath covenanted with his people, O house of Israel;
5 Therefore, when these works and the works which shall be wrought among you hereafter shall come forth from the Gentiles, unto your seed which shall dwindle in unbelief because of iniquity;
6 For thus it behooveth the Father that it should come forth from the Gentiles, that he may show forth his power unto the Gentiles, for this cause that the Gentiles, if they will not harden their hearts, that they may repent and come unto me and be baptized in my name and know of the true points of my doctrine, that they may be numbered among my people, O house of Israel;
7 And when these things come to pass that thy seed shall begin to know these things—it shall be a sign unto them, that they may know that the work of the Father hath already commenced unto the fulfilling of the covenant which he hath made unto the people who are of the house of Israel.
8 And when that day shall come, it shall come to pass that kings shall shut their mouths; for that which had not been told them shall they see; and that which they had not heard shall they consider.
9 For in that day, for my sake shall the Father work a work, which shall be a great and a marvelous work among them; and there shall be among them those who will not believe it, although a man shall declare it unto them.
10 But behold, the life of my servant shall be in my hand; therefore they shall not hurt him, although he shall be marred because of them. Yet I will heal him, for I will show unto them that my wisdom is greater than the cunning of the devil.
11 Therefore it shall come to pass that whosoever will not believe in my words, who am Jesus Christ, which the Father shall cause him to bring forth unto the Gentiles, and shall give unto him power that he shall bring them forth unto the Gentiles, (it shall be done even as Moses said) they shall be cut off from among my people who are of the covenant.
12 And my people who are a remnant of Jacob shall be among the Gentiles, yea, in the midst of them as a lion among the beasts of the forest, as a young lion among the flocks of sheep, who, if he go through both treadeth down and teareth in pieces, and none can deliver.
13 Their hand shall be lifted up upon their adversaries, and all their enemies shall be cut off.
14 Yea, wo be unto the Gentiles except they repent; for it shall come to pass in that day, saith the Father, that I will cut off thy horses out of the midst of thee, and I will destroy thy chariots;
15 And I will cut off the cities of thy land, and throw down all thy strongholds;
16 And I will cut off witchcrafts out of thy land, and thou shalt have no more soothsayers;
17 Thy graven images I will also cut off, and thy standing images out of the midst of thee, and thou shalt no more worship the works of thy hands;
18 And I will pluck up thy groves out of the midst of thee; so will I destroy thy cities.
19 And it shall come to pass that all lyings, and deceivings, and envyings, and strifes, and priestcrafts, and whoredoms, shall be done away.
20 For it shall come to pass, saith the Father, that at that day whosoever will not repent and come unto my Beloved Son, them will I cut off from among my people, O house of Israel;
21 And I will execute vengeance and fury upon them, even as upon the heathen, such as they have not heard.
22 But if they will repent and hearken unto my words, and harden not their hearts, I will establish my church among them, and they shall come in unto the covenant and be numbered among this the remnant of Jacob, unto whom I have given this land for their inheritance;
23 And they shall assist my people, the remnant of Jacob, and also as many of the house of Israel as shall come, that they may build a city, which shall be called the New Jerusalem.
24 And then shall they assist my people that they may be gathered in, who are scattered upon all the face of the land, in unto the New Jerusalem.
25 And then shall the power of heaven come down among them; and I also will be in the midst.
26 And then shall the work of the Father commence at that day, even when this gospel shall be preached among the remnant of this people. Verily I say unto you, at that day shall the work of the Father commence among all the dispersed of my people, yea, even the tribes which have been lost, which the Father hath led away out of Jerusalem.
27 Yea, the work shall commence among all the dispersed of my people, with the Father to prepare the way whereby they may come unto me, that they may call on the Father in my name.
28 Yea, and then shall the work commence, with the Father among all nations in preparing the way whereby his people may be gathered home to the land of their inheritance.
29 And they shall go out from all nations; and they shall not go out in haste, nor go by flight, for I will go before them, saith the Father, and I will be their rearward.
"The Savior said when these tribulations should take place, it should be committed to a man who should be a witness over the whole world: the keys of knowledge, power and revelations should be revealed to a witness who should hold the testimony of the world.....All testimony is that the Lord in the last days would commit the keys of the Priesthood to a witness over all people. Has the Gospel of the kingdom commenced in the last days? And will God take it from the man until He takes him Himself? I have read it precisely as the words flowed from the lips of Jesus Christ John the Revelator saw an angel flying through the midst of heaven, having the everlasting Gospel to preach unto them that dwell on the earth. The scripture is ready to be fulfilled when great wars, famines, pestilence, great distress, judgments, &c., are ready to be poured out on the inhabitants of the earth. John saw the angel having the holy Priesthood, who should preach the everlasting Gospel to all nations God had an angel---a special messenger---ordained and prepared for that purpose in the last days. Woe, woe be to that man or set of men who life up their hands against God and His witness in these last days: for they shall deceive almost the very chosen ones!" (TPJS 364)
``Behold, the Lord hath a might and strong one, which as a tempest of hail and destroying storm, as a flood of mighty waters overflowing, shall cast down to the earth with the hand.'' (Isaiah 28:2)
"And it shall come to pass that I, the Lord God, will send one mighty and strong, holding the scepter of power in his hand, clothed with light for a covering, whose mouth shall utter words, eternal words; while his bowels shall be a fountain of truth, to set in order the house of God, and to arrange by lot the inheritances of the saints whose names are found, and the names of their fathers, and of their children, enrolled in the book of the law of God. While that man, who was called of God and appointed, that putteth forth his hand to steady the ark of God, shall fall by the shaft of death, like as a tree that is smitten by the vivid shaft of lightning. And all they who are not found written in the book of remembrance shall find none inheritance in that day, but they shall be cut asunder, and their portion shall be appointed them among unbelievers, where are wailing and gnashing of teeth.'" (D&C 85:7-9)
We know that this person is among the descendants of Lehi, either living with them or being a descendant himself.
"Wherefore, because of this covenant thou art blessed; for thy seed shall not be destroyed, for they shall hearken unto the words of the book. And there shall rise up one mighty among them [the seed of Lehi], who shall do much good, both in word and in deed, being an instrument in the hands of God, with exceeding faith, to work mighty wonders, and do that thing which is great in the sight of God, unto the bringing to pass much restoration unto the house of Israel, and unto the seed of thy brethren." (2 Nephi 3:23-24)
1 And there shall come forth a rod out of the stem of Jesse, and a Branch shall grow out of his roots:
2 And the spirit of the Lord shall rest upon him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and of the fear of the Lord;
3 And shall make him of quick understanding in the fear of the Lord: and he shall not judge after the sight of his eyes, neither reprove after the hearing of his ears:
4 But with righteousness shall he judge the poor, and reprove with equity for the meek of the earth: and he shall smite the earth with the rod of his mouth, and with the breath of his lips shall he slay the wicked.
5 And righteousness shall be the girdle of his loins, and faithfulness the girdle of his reins.
6 The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them.
7 And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox.
8 And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice’ den.
9 They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the Lord, as the waters cover the sea.
10 ¶And in that day there shall be a root of Jesse, which shall stand for an ensign of the people; to it shall the Gentiles seek: and his rest shall be glorious.
11 And it shall come to pass in that day, that the Lord shall set his hand again the second time to recover the remnant of his people, which shall be left, from Assyria, and from Egypt, and from Pathros, and from Cush, and from Elam, and from Shinar, and from Hamath, and from the islands of the sea.
12 And he shall set up an ensign for the nations, and shall assemble the outcasts of Israel, and gather together the dispersed of Judah from the four corners of the earth.
13 The envy also of Ephraim shall depart, and the adversaries of Judah shall be cut off: Ephraim shall not envy Judah, and Judah shall not vex Ephraim.
14 But they shall fly upon the shoulders of the Philistines toward the west; they shall spoil them of the east together: they shall lay their hand upon Edom and Moab; and the children of Ammon shall obey them.
15 And the Lord shall utterly destroy the tongue of the Egyptian sea; and with his mighty wind shall he shake his hand over the river, and shall smite it in the seven streams, and make men go over dryshod.
16 And there shall be an highway for the remnant of his people, which shall be left, from Assyria; like as it was to Israel in the day that he came up out of the land of Egypt. (Isaiah 11)
What is the root of Jesse spoken of in the 10th verse of the 11th chapter?
"Behold, thus saith the Lord, it is a descendant of Jesse, as well as of Joseph, unto whom rightly belongs the priesthood, and the keys of the kingdom, for an ensign, and for the gathering of my people in the last days." (D&C 113:5-6)
"...the throne & kingdom of David is to be taken from him & given to another by the name of David in the last days, raised up out of his linage.'' (Words of Joseph Smith, 10 Mar 1844)
"10 And in that day there shall be a root of Jesse, which shall stand for an ensign of the people; to it shall the Gentiles seek; and his rest shall be glorious.
11 And it shall come to pass in that day that the Lord shall set his hand again the second time to recover the remnant of his people which shall be left, from Assyria, and from Egypt, and from Pathros, and from Cush, and from Elam, and from Shinar, and from Hamath, and from the islands of the sea.
12 And he shall set up an ensign for the nations, and shall assemble the outcasts of Israel, and gather together the dispersed of Judah from the four corners of the earth.'" (2 Nephi 21:10-12)
It's actually surprising to see how many references to this fellow there are in the scriptures.
1 Awake, awake; put on thy strength, O Zion; put on thy beautiful garments, O Jerusalem, the holy city: for henceforth there shall no more come into thee the uncircumcised and the unclean.
2 Shake thyself from the dust; arise, and sit down, O Jerusalem: loose thyself from the bands of thy neck, O captive daughter of Zion.
3 For thus saith the Lord, Ye have sold yourselves for nought; and ye shall be redeemed without money.
4 For thus saith the Lord God, My people went down aforetime into Egypt to sojourn there; and the Assyrian oppressed them without cause.
5 Now therefore, what have I here, saith the Lord, that my people is taken away for nought? they that rule over them make them to howl, saith the Lord; and my name continually every day is blasphemed.
6 Therefore my people shall know my name: therefore they shall know in that day that I am he that doth speak: behold, it is I.
7 ¶How beautiful upon the mountains are the feet of him that bringeth good tidings, that publisheth peace; that bringeth good tidings of good, that publisheth salvation; that saith unto Zion, Thy God reigneth!
8 Thy watchmen shall lift up the voice; with the voice together shall they sing: for they shall see eye to eye, when the Lord shall bring again Zion.
9 ¶Break forth into joy, sing together, ye waste places of Jerusalem: for the Lord hath comforted his people, he hath redeemed Jerusalem.
10 The Lord hath made bare his holy arm in the eyes of all the nations; and all the ends of the earth shall see the salvation of our God.
11 ¶Depart ye, depart ye, go ye out from thence, touch no unclean thing; go ye out of the midst of her; be ye clean, that bear the vessels of the Lord.
12 For ye shall not go out with haste, nor go by flight: for the Lord will go before you; and the God of Israel will be your rearward.
13 ¶Behold, my servant shall deal prudently, he shall be exalted and extolled, and be very high.
14 As many were astonied at thee; his visage was so marred more than any man, and his form more than the sons of men:
15 So shall he sprinkle many nations; the kings shall shut their mouths at him: for that which had not been told them shall they see; and that which they had not heard shall they consider. (Isaiah 52)