We believe in one true Church, and that is the Church of Jesus Christ.
.
We are not taking away the truths of all other churches. There are truths to each of them, but they do not have the keys or authority to act in the name of Jesus Christ.
.
They have the form of godliness and are doing many wonderful things, but they do not have the Gospel’s fullness.
.
How do we know this?
.
Joseph Smith taught us—”I was answered that I must join none of them, for they were all ​​​wrong​; and the Personage who addressed me said that all their creeds were an abomination in his sight; that those ​​​professors​ were all ​​​corrupt​; that: “they ​​​draw near​ to me with their lips, but their ​​​hearts​ are far from me, they teach for doctrines the ​​​commandments​ of men, having a form of godliness, but they deny the ​​​power​ thereof.” JSH 1:19.
.
What then is our position and what stance do we take?
.
“The position that The Church of Jesus Christ of Latter-day Saints is the only true church upon the face of the earth is fundamental.
.
Perhaps it would be more convenient and palatable and popular if we were to avoid it; nevertheless, we are under a sacred obligation and a sacred trust to hold to it.
.
It is not merely an admission; it is a positive declaration. It is so fundamental that we cannot yield on this point…
.
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.” —Elder Packer.