Joseph Fielding Smith
"I would like to call your attention to one thing in the Book of Mormon. The Lord has promised us greater knowledge, greater understanding than we find in the Book of Mormon, when we are prepared to receive it. When the brother of Jared went upon the mount to have the Lord touch stones to give them light to light their way across the great ocean, the Lord revealed to him the history of this world from the beginning of it to the end. We do not have it.
"I am going to read one or two passages of scripture from the Book of Mormon in relation to that matter. ‘And he’ (that is, Christ) ’did expound all things, even from the beginning until the time that he should come in his glory -- yea, even all things which should come upon the face of the earth, even until the elements should melt with fervent heat, and the earth should be wrapt together as a scroll, and the heavens and the earth should pass away; …’ (3 Nephi 26:3.)
"All of that was written and given to the Nephites. We do not have that record, and the Lord said this -- which is concerning us particularly -- and Mormon wrote it: (quotes 3 Nephi 26:8-10)
"I say that when the brother of Jared went on the mount, the Lord revealed the history of this earth to him from the beginning to the end thereof, but we do not have it. But when the Nephites became righteous, after the visit of the Son of God, the Lord revealed that record to them, and then when they began to fall away, he took the record away again and hid it up. Here is what the Lord says about it.
’And after Christ truly had showed himself unto his people, he commanded that they should be made manifest.’ (That is, the full record.)
’And now, after that, they have all dwindled in unbelief; and there is none save it be the Lamanites, and they have rejected the gospel of Christ; therefore I am commanded that I should hide them up again in the earth.’
’…And in that day that they shall exercise faith in me, saith the Lord, even as the brother of Jared did, that they may become sanctified in me, then will I manifest unto them the things which the brother of Jared saw, even to the unfolding unto them all my revelations, saith Jesus Christ, the Son of God, the Father of the heavens and of the earth, and all things that in them are.’ (Ether 4:2,3,7)
“Now the Lord has placed us on probation as members of the Church. He has given us the Book of Mormon, which is the lesser part, to build up our faith through our obedience to the counsels which it contains, and when we ourselves, members of the Church, are willing to keep the commandments as they have been given to us and show our faith as the Nephites did for a short period of time, then the Lord is ready to bring forth the other record and give it to us, but we are not ready now to receive it. Why? Because we have not lived up to the requirements in this probationary state in the reading of the record which had been given to us and in following its counsels.” (Conference Report, Oct. 1961, pp. 19-20)
Neal A. Maxwell
“So it is that ’all things must come to pass in their own time.’ (D&C 64:32.) This is cause and reason for patience and perspective amidst the macro plan! Such unfoldingness reflects the tutoring of a just and a long-suffering Lord…. Besides, we have a notable lack of capacity to appreciate things that, like water out of a fire hydrant, come in a rush. Hence the Lord meters out divine disclosure according to what is deserved and usable. He has warned us: ’Murmur not because of the things which thou hast not seen, for they are withheld from thee and from the world, which is wisdom in me in a time to come’ (D&C 25:4.).” (Meek and Lowly, p. 91)