The Church and Kingdom of the last days "shall never be destroyed" or "be left to other people" but "shall stand for ever" (Daniel 2:44).

Daniel prophesied that in the latter days the God of heaven would, set up a kingdom, which should never be destroyed and that this Kingdom would not be left to other people, but would eventually break in pieces all worldly kingdoms, and that this, God’s Kingdom to be set up on the earth in the latter days, would stand for ever. That Kingdom was compared to a stone cut out of a mountain without hands, signifying that it was God’s work and kingdom and not man’s. Set up by God on the earth, it was to roll forth and grow larger until it would fill the earth (Daniel 2:34-35, 44). This is also discussed in the revelatory prayer through the Prophet Joseph Smith found in section 65 of the Doctrine and Covenants.

Hearken, and lo, a voice as of one sent down from on high, who is mighty and powerful, whose going forth is unto the ends of the earth, yea, whose voice is unto men--Prepare ye the way of the Lord, make his paths straight. 

The voice of the Lord, his word, the Gospel or glad tidings of the King is unto all men. It is to go forth “unto the ends of the earth” for the purpose of preparing way before the Lord who is the King who is coming back to the earth to reign as King of Kings.

The keys of the kingdom of God are committed unto man on the earth

The Keys of the Kingdom are committed to man on the earth (This is 1831). The Church had just been restored a year before this. The keys were already committed to Joseph Smith and Oliver Cowdery from heavenly messengers sent by God from heaven. These are the keys of the kingdom committed to them by which the Church of Christ was organized and through which the Gospel could be legally preached and administered. They are on the earth. And where the keys are, there is the Kingdom. 

And from thence shall the gospel roll forth unto the ends of the earth, as the stone which is cut out of the mountain without hands shall roll forth, until it has filled the whole earth.

This is the “Gospel of the Kingdom” and it is to go forth from on the earth unto the ends of the earth. Unlike previous times, The stone set up already by God in the latter days is not to be removed or taken away. It is set up to go forth and grow and be prepared to meet the King on the earth when he comes. But the Gospel of the Kingdom cannot roll forth on the earth without the Kingdom itself or without the keys and authority to administer it with its covenants and ordinances. Hence the need for the keys to be first bestowed upon the Lord’s servants on the earth, as they were upon Joseph Smith and Oliver Cowdery. The Gospel rolls forth as the Kingdom does and it rolls forth with the Kingdom. They go together, hand in hand, the Kingdom with its message rolling forth as a stone to gather up the elect who help who then assist in building up the Kingdom and preparing to meet their King.

Yea, a voice crying—prepare ye the way of the Lord, prepare ye the supper of the Lamb, make ready for the Bridegroom

The Kingdom with its Gospel rolls forth inviting guests to the supper. Only those who are a part of the Kingdom get to go to the supper of the King. 

Pray unto the Lord, call upon his holy name, make known his wonderful works among the people. Call upon the Lord that his kingdom may go forth upon the earth, that inhabitants thereof may receive it

The Kingdom grows on the earth as people on the earth receive and obey the Gospel and thereby join it.

And be prepared for the days to come in which the Son of Man shall come down in heaven clothed in the brightness of his glory to meet the kingdom of God which is set up on the earth.

Notice that the Kingdom is still on the earth when the Son of Man returns since the keys were first committed to Joseph Smith and it has remained there since it was first set up and established by God. They have not returned to heaven again and left the Saints alone. The Bride, that is the Church, still has the Keys of the Kingdom and she has remained on the earth with keys of power to prepare the Kingdom already set up on earth for Bridegroom’s arrival.

Wherefore, may the kingdom of God go forth, that the kingdom of heaven may come , that thou, O God, mayest be glorified in heaven so on earth, that thine enemies may be subdued; for thine is the honor, power and glory, forever and ever. Amen (LDS D&C 65).

The Kingdom, represented by Daniel’s stone can only go forth and fill the earth by growing. It grows as people join it. They join it by receiving the Gospel message and its saving covenants. So it is necessary that the Kingdom set up on the earth, originally small, grow and increase, in order that God may be glorified both on earth and in heaven and in order to subdue the enemies of God in the latter days. It is clear from the above that the Gospel and the Kingdom set up by God through the ministering of heavenly messengers sent from heaven to Joseph Smith was not to be lost or fail in its mission, but starting small, would grow and eventually subdue its enemies and fill the earth.

Further support of this can be found in the dedicatory prayer of the Kirtland Temple in 1836. Joseph Smith identified this latter-day Kingdom, spoken of by the prophets, with the Lord’s Church which had recently been restored to the earth. “Remember all thy church, O Lord, with all their families, and all their immediate connections, with all their sick and afflicted ones, with all the poor and meek of the earth; that the kingdom, which thou hast set up without hands, may become a great mountain and fill the whole earth; (Latter Day Saints’ Messenger and Advocate 2/6 [March 1836]: 280; LDS D&C 109:72). The revelations call the Lord’s Church the “last kingdom”  (D&C 88:70, 74), which administers the “last covenant” and which is to go forth for the “last time.” It was to “never be destroyed” and would “not be left to other people” and “would stand forever.”