6 And now there cannot be written in this book even a hundredth part of the things which Jesus did truly teach unto the people;
7 But behold the plates of Nephi do contain the more part of the things which he taught the people.
8 And these things have I written, which are a lesser part of the things which he taught the people; and I have written them to the intent that they may be brought again unto this people, from the Gentiles, according to the words which Jesus hath spoken.
9 And when they shall have received this, which is expedient that they should have first, to try their faith, and if it shall so be that they shall believe these things then shall the greater things be made manifest unto them.
10 And if it so be that they will not believe these things, then shall the greater things be withheld from them, unto their condemnation.
11 Behold, I was about to write them, all which were engraven upon the plates of Nephi, but the Lord forbade it, saying: I will try the faith of my people.
(3 Nephi 26:6-11)
During his description of the ministry of the Savior on the American continent, Mormon inserts an editorial note. I’m only giving you part of Jesus’s teachings, he says. There are many more, which are written on the plates of Nephi: more than a hundred times as many. I can imagine the effort Mormon made to study carefully all of the recorded teachings of Jesus and then to select those parts that he would include in this record. I can easily imagine Mormon, who decided to include the small plates of Nephi without abridgment because he liked them so much (Words of Mormon 1:3-6), deciding to include all of the teachings of Jesus as well, only to be told by God that he could only include a small portion. He was not allowed to give us the entire record. Why? Because God wanted to try our faith first.
Alma taught that those who harden their hearts receive “the lesser portion of the word,” while those who don’t harden their hearts receive more and more of God’s word, until “until it is given unto [them] to know the mysteries of God until [they] know them in full” (Alma 12:9-10). Moroni taught that when we overcome our unbelief and exercise sufficient faith, then we will eventually have access to all of God’s revelations. Some of those revelations were received by the brother of Jared. Moroni faithfully recorded those but did not include them in this book, because we aren’t ready to receive them yet (Ether 4:4-7). The combined message of Alma, Mormon, and Moroni is clear: More truth is available, but God wants to see what you will do with the knowledge He has already given you before He gives you more.
Today, I will remember that my ability to receive additional knowledge from God is dependent on my treatment of the knowledge He has already given me. If I open my heart and exercise faith based on the knowledge I have already received, then I will receive more. But if I harden my heart and fail to exercise faith, then additional knowledge will not be available to me. My attitude and my actions determine my ability to continue to acquire spiritual knowledge.