There are at least two Book of Mormon passages that indicate the church in this dispensation will continue on faithful until the return of the Savior.
1 Nephi 14:12-14–Nephi saw in vision the “church of the Lamb of God” in the last days. Although “its numbers were few,” “the saints of God, were also upon all the face of the earth.” In time “the power of the Lamb of God…descend[s] upon the saints of the church of the Lamb, and upon the covenant people of the lord, who [are] scattered upon all the face of the earth; and they [are] armed with righteousness and with the power of God in great glory.” Subsequently he saw the destruction of the wicked at the Savior’s second coming. It is clear that the Latter-day Church would be “upon all the face of the earth” which is something that we could only begin to realistically envision in recent decades with the radical expansion of the number of stakes and temples across the entire world.
Jacob 5:70-72, 75 –Zenos saw that before “the end cometh,” the Lord of the vineyard would send “his servant” down who “brought other servants; and they were few. And the Lord of the vineyard said unto them: Go to, and labor in the vineyard, with your might. For behold, this is the last time that I shall nourish my vineyard; for the end is nigh at hand, and the season speedily cometh; and if ye labor with your might with me ye shall have joy in the fruit which I shall lay up unto myself against the time which will soon come. And it came to pass that the servants did go and labor with their mights; and the Lord of the vineyard labored also with them; and they did obey the commandments of the Lord of the vineyard in all things.… And it came to pass that when the Lord of the vineyard saw that his fruit was good, and that his vineyard was no more corrupt, he called up his servants, and said unto them: Behold, for this last time have we nourished my vineyard; and thou beholdest that I have done according to my will... ”
This passage is clearly speaking of what started in 1820 and continues until this day. This is especially evident by comparing the above language in Jacob 5 with what the Lord said in several early revelations to the prophet Joseph Smith. A few examples should suffice:
“For behold, the field is white already to harvest; and it is the eleventh hour, and the last time that I shall call laborers into my vineyard. And my vineyard has become corrupted every whit; and there is none which doeth good save it be a few…” (D&C 33:3-4)
“Wherefore lay to with your might and call faithful laborers into my vineyard, that it may be pruned for the last time” (D&C 39:17)
“Wherefore, labor ye, labor ye in my vineyard for the last time–for the last time call upon the inhabitants of the earth…” (D&C 43:28)
From these revelations it is abundantly clear that God sent his servants to nourish his vineyard for the last time with the restoration of the Church of Jesus Christ of Latter-day Saints in 1830. His servants are “obey[ing] the commandments of the Lord of the vineyard in all things” and He is “do[ing] according to [his] will.” He is laboring with them! There isn’t room in Zenos’ allegory for another falling away and restoration before the coming of the Lord of the Vineyard. Since 1830 we have been in the period of “the last time,” what the Lord has called the Latter days or “the eleventh hour,” and his servants have been (and are now!) faithfully laboring in the vineyard. They will do so until he returns.
Does this mean that his servants can’t occasionally miss a branch that should be pruned or a weed that should be pulled? Or, on the other hand, that sometimes a branch is loped off that shouldn’t be? I don’t think we can expect that kind of perfection out of humans, but they are doing a good job taking care of the vineyard and preparing it for the harvest which is soon to come. They are faithful servants.
There is another interesting scripture found in the Doctrine and Covenants regarding the kingdom of God. Section 65 should be read in its entirety, but verse 2 is particularly meaningful in this context: “The keys of the kingdom of God are committed unto man on the earth, 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 doesn’t leave room for the kingdom of God or the Church having to get re-booted or re-restored, does it? This should be compared to Joseph Smith’s bold statement commonly called “the Standard of Truth:”
“[T]he Standard of Truth has been erected; no unhallowed hand can stop the work from progressing; persecutions may rage, mobs may combine, armies may assemble, calumny may defame, but the truth of God will go forth boldly, nobly, and independent, till it has penetrated every continent, visited every clime, swept every country, and sounded in every ear; till the purposes of God shall be accomplished, and the Great Jehovah shall say the work is done.”
Was Joseph Smith speaking prophetically or not? If so, then the truth of God has been and will continue to “go forth” uninterrupted until “the work is done” which will only happen when Christ reigns personally again upon the earth.
Strong Reasons 