Charity Never Faileth, of course, is the motto of the Relief Society. Joseph Smith read 1 Corinthians 13 (apparently the whole chapter, not just these three words) in one of his first speeches to the women in Nauvoo, at the organization of the Relief Society.
In Paul’s Greek, the word for faileth literally means to “fall, i.e., dead,” and in Mormon’s war-torn world, to say something like charity would never die, or never fall dead, or come to naught, was a potent way of ending his promise about the unending salvific role of charity. Charity, Mormon claimed, was an immortal power, and that reassurance would have been very heartening for his people to hear, who were desperately worried about the survival of themselves individually and of their posterity. To be taught that they would not fail, or ultimately perish, so long as they had charity, added purpose and a desire for them to “lay hold on every good thing.”
Mormon alone then went on to provide an additional elevated definition of what the scriptures mean by charity, by this love. “Charity is the pure love of Christ” (7:47). The word “of” may be understood in several ways. It may refer to charity being Christ’s love of all mankind, and thus it may also mean that true charity refers to the love that one has when one loves as Christ loves. Additionally, it may also refer to the way that a person purely loves Christ, for His faithful flock may love Him, with charity then meaning our love of Him, of Christ. Scholars accept these different possible meanings of the English word of in that sentence. There is no reason it cannot be all three. Mormon provides a powerful and effective explanation of how one may develop faith, hope, and charity and weave them together to humanize the path of returning to our Father in Heaven.
Matthew O. Richardson, “‘The Pure Love of Christ’: The Divine Precept of Charity in Moroni 7,” in Living the Book of Mormon: Abiding by Its Precepts, ed. Gaye Strathearn and Charles Swift (Salt Lake City and Provo, UT: Deseret Book and BYU Religious Studies Center, 2007), 290–301.