What is meant by the “mysteries of God”? Essentially, the mysteries of God constitute the principles and ordinances of salvation and exaltation—the essence of the gospel of Jesus Christ. Elder Bruce R. McConkie gives the following explanation:
A mystery is something which cannot be explained, either because it is beyond human comprehension in general, or because some particular man has not learned enough to understand it. Accordingly, some matters of doctrine, philosophy, or science may be a mystery to one person and not to another. When a thing is understood it is no longer a mystery. In the eternal sense there are no mysteries; all things are known to and understood by Deity; and there will be no mysteries among exalted beings, for they too shall know all things.
A knowledge of the mysteries of God comes by obedience to gospel law. “It is given unto many to know the mysteries of God,” Amulek taught. “He that will harden his heart, the same receiveth the lesser portion of the word; and he that will not harden his heart, to him is given the greater portion of the word, until it is given unto him to know the mysteries of God until he know them in full” (Alma 12:9–11) [Compare also D&C 42:61–65; 6:7, 11; 8:11; 11:7; 76:5–10]. (Mormon Doctrine, 2d ed. [Salt Lake City: Bookcraft, 1966], 523)