The Only True Church
So what do we mean? Frankly I doubt that we are usually sure. What we say has a liturgical and rhetorical meaning as much as or more than a referential one. We mean at least to show our loyalty to the LDS Church and the importance that our membership has to us. We mean to avow that the LDS Church is unlike other churches in significant ways. Those liturgical and rhetorical meanings are important, not to be depreciated. Yet I think we also mean more.
It seems to me that the phrase "true church" means what it does as a parallel to Old Testament phrases like "true God." The Hebrew word used in the latter phrase is emet: firm, established, faithful, reliable.
On that parallel, besides all of the other things implied when we say that the LDS Church is the true church, we testify that it has been established by God. We say that it is firm, faithful, reliable as the bearer of God's word.
But to say that is not to say that no other churches could have been established by him or that none other is faithful. If, as the First Presidency's message avers, God has also revealed some measure of his word to others, including non-Christians, then there is an important sense in which he has also established the churches (using the term broadly) of those who have received his light.
To say that the LDS is the true Church is to say that, as established, firm, and reliable as other churches may be, the LDS Church is the most established, reliable, and firm church given by God.
That may also be an arrogant claim. If so, we will have to live with it. God's chosen people have lived with that supposed arrogance for millennia, not as special people chosen out of the rest so much as those chosen as priests for the rest of us (Ex. 19:6).
Mormons, too, will have to learn to live among their friends believing that God has chosen to use them as a special vehicle for his revelations and authority and priesthood. The LDS Church is not the only vehicle, but the Mormon testimony is that of all the ways in which God has revealed himself in the world, he has nowhere more fully done so than in The Church of Jesus Christ of Latter-day Saints.
James Faulconer is a Richard L. Evans Professor of Religious Understanding at Brigham Young University, where he has taught philosophy since 1975.