“There are in the gospel such things as mysteries. A mystery is, of course, some truth which is not understood. All the principles of the gospel and all truth pertaining to the salvation of men are simple when understood. Until it is understood, however, a simple truth may be a great mystery … .
“To understand spiritual things, a man must have spiritual discernment, that is, guidance by the Holy Ghost. For this reason we are confirmed and receive the gift of the Holy Ghost” (Smith, Doctrines of Salvation, 1:296–97).