D&C 121

As the Prophet Joseph Smith suffered in Liberty Jail, he penned with inspiration -

"God shall give unto you knowledge by his Holy Spirit, yea, by the unspeakable gift of the Holy Ghost..." (Doctrine and Covenants Section 121:26)

Hoyt W. Brewster explained -

"As an adjective, unspeakable denotes something that is inexpressible or unutterable. As a noun, it refers to "a being or thing beyond the power of language to describe." 612Experiences with the Spirit of the Holy Ghost are frequently unspeakable in that they are beyond one's capacity to describe in mortal words. To quote Elder Neal A. Maxwell, "the tongue cannot tell all it knows" (En., May 1976, p. 26).

Of this "unspeakable gift", the Prophet wrote -

"...that has not been revealed since the world was until now; 27 Which our forefathers have awaited with anxious expectation to be revealed in the last times, which their minds were pointed to by the angels, as held in reserve for the fulness of their glory..." (Doctrine and Covenants Section 121:26 - 27)

Even though the Gift of the Holy Ghost has been present throughout the history of the world, it is in this last dispensation that the Gift of the Holy Ghost will become even more unspeakable than any previous dispensation. Quoting President Harold B. Lee -

“...more perfected than in the past dispensations...” (Stand Ye in Holy Places, p. 273; see also p. 322).

And it was to be in this last or final dispensation that Lord promised by this unspeakable gift that great knowledge would be given -

"A time to come in the which nothing shall be withheld, whether there be one God or many gods, they shall be manifest.
29 All thrones and dominions, principalities and powers, shall be revealed and set forth upon all who have endured valiantly for the gospel of Jesus Christ.
30 And also, if there be bounds set to the heavens or to the seas, or to the dry land, or to the sun, moon, or stars—
31 All the times of their revolutions, all the appointed days, months, and years, and all the days of their days, months, and years, and all their glories, laws, and set times, shall be revealed in the days of the dispensation of the fulness of times—
32 According to that which was ordained in the midst of the Council of the Eternal God of all other gods before this world was, that should be reserved unto the finishing and the end thereof, when every man shall enter into his eternal presence and into his immortal rest." (Doctrine and Covenants Section 121:28 - 32)

All truth shall be revealed and it cannot be stopped, for -

"How long can rolling waters remain impure? What power shall stay the heavens? As well might man stretch forth his puny arm to stop the Missouri river in its decreed course, or to turn it up stream, as to hinder the Almighty from pouring down knowledge from heaven upon the heads of the Latter-day Saints." (Doctrine and Covenants Section 121:33)

I believe great knowledge has been and will continue to be revealed both personally and collectively in these last days. As Isaiah prophecied -

"Bind up the testimony, seal the law among my disciples." (Old Testament Isaiah 8:16)