The key to understanding spiritual things is to “inquire of the Lord.” Nephi recognizes that Laman and Lemuel had failed to look to the Lord because of the hardness of their hearts. Failure to understand the Book of Mormon, or other words coming from the Lord or his servants, is for the same reason today. Elder Marion D. Hanks commented on the words of Nephi cited above:
There is no way to understand spiritual truth except through the Spirit of God. Natural ability, brilliance of intellect, training, diligent search are all inadequate of themselves to give understanding of spiritual things if he who possess them is not led by the Spirit. “… to be learned is good if they hearken unto the counsels of God.” [2 Nephi 9:29]
The Prophet Lehi tried with great patience to teach his sons Laman and Lemuel the principles of the gospel, but they would not learn. They were unable to understand because they would not humble themselves and call on the Lord; therefore, they could not receive a knowledge of truth through the Spirit… .
The only way to know spiritual truth is through the Spirit of God which may be enjoyed only by those who humble themselves and call upon him and hearken to his voice. Nothing is more clear in scripture or in life than this truth. The things of the Spirit are “hard to be understood, save a man should inquire of the Lord; …” in sincerity and humility. Through “study and also by faith,” through reverent search and humble prayer, men can know with certain assurance the things of God.
For those who will not pay the price, the truths of the gospel will always be a “stumbling block,” “foolishness,” “hard to be understood.” In their pride and stubbornness they fail to learn the most important truths of eternity. [Improvement Era, Aug. 1961, 587]
After quoting 1 Nephi 15:3, Elder Neal A. Maxwell commented:
This failure to believe in a revealing God was especially basic. Some moderns who wish to distance themselves from God try placing His pavilion firmly in the past. By believing in such a disabled God, people can do pretty much as they please. It is then not many steps further to saying there is no God, and therefore no law and no sin! [see 2 Nephi 2:13; see also Alma 30:28]
Like Laman and Lemuel, many today would consign God only to the past; He thereby ceases to be the constant God of yesterday, today, and tomorrow (see 2 Nephi 27:23). Actually, God has the past, present, and future ever before Him, constituting “an eternal now.” [Teachings of the Prophet Joseph Smith, sel. Joseph Fielding Smith (1976), 220; see also D & C 130:7]
In short, Laman and Lemuel’s own lack of character kept them from understanding the perfect character of God! No wonder the Prophet Joseph Smith said, “If men do not comprehend the character of God, they do not comprehend themselves” (Teachings of the Prophet Joseph Smith, 343). [CR, Oct. 1999, 5]