Why are these plates of Mormon sealed? The answer is obvious. They contain spiritual truths beyond our present ability to receive. Milk must precede meat, and whenever men are offered more of the mysteries of the kingdom than they are prepared to receive, it affects them adversely. (New Witness, p. 443.)
“The Things Which Are Sealed Shall Not Be Delivered in the Day of the Wickedness and Abominations of the People”
Moroni edited the record of the Jaredites, his edited record becoming that which we call the book of Ether. Having read the marvelous things contained in the sealed portion, Moroni observed: “I have written upon these plates the very things which the brother of Jared saw; and there never were greater things made manifest than those which were made manifest unto the brother of Jared. Wherefore the Lord hath commanded me to write them; and I have written them. And he commanded me that I should seal them up; and he also hath commanded that I should seal up the interpreters [the stones to be used for their subsequent translation], according to the commandment of the Lord.” (Ether 4:4-5.)