Ether 3 – 4
The plain revelations given to John, Nephi, the Brother of Jared, Moses, and Enoch (that we know of) were written by Moroni and sealed up. They would take about 1000 pages similar to the pages in our modern Book of Mormon. When the people had a full and general knowledge of Christ among them they had that knowledge, but at the times when wickedness becomes common among them the knowledge is sealed up again and hidden. I would be surprised if that knowledge ever became generally available again before the second coming of Christ. On the other hand, those who are faithful are promised that they shall receive, as Mosiah did even before it was made publicly known. I would hope to live such that I could be worthy of that honor.