Boyd K. Packer, 1971 - "The gospel might be likened to the keyboard of a piano"

"The gospel might be likened to the keyboard of a piano - a full keyboard with a selection of keys on which one who is trained can play a variety without limits; a ballad to express love, a march to rally, a melody to soothe, and a hymn to inspire; an endless variety to suit every mood and satisfy every need.

"How shortsighted it is, then, to choose a single key and endlessly tap out the monotony of a single note, or even two or three notes, when the full keyboard of limitless harmony can be played.

"How disappointing when the fullness of the gospel, the whole keyboard, is here upon the earth, that many churches tap on a single key. The note they stress may be essential to a complete harmony of religious experience, but it is, nonetheless, not all there is. It isn't the fullness.

"For instance, one taps on the key of faith healing, to the neglect of many principles that would bring greater strength than faith healing itself. Another taps on an obscure key relating to the observance of the Sabbath - a key that would sound different indeed, played in harmony with the essential notes on the keyboard. A key used like that can get completely out of tune. Another repeats endlessly the key that relates to the mode of baptism and taps one or two other keys as though there were not a full keyboard. And again, the very key he uses, essential as it is, just doesn't sound complete when played alone to the neglect of the others."

https://www.lds.org/ensign/1971/12/the-only-true-and-living-church?lang=eng