Translation: This verse is one of the most difficult in the entire text of the Book of Mormon. Multiple allusions are mixed into Joseph’s translation of Moroni’s words, but the allusions confuse, rather than clarify. Here is my attempt to sort out Moroni’s intention from the odd combination of allusions.
In saying, “if the Gentiles have not charity, because of our weakness,” Moroni is alluding to his discussion of Gentiles mocking the Book of Mormon because of the writing’s weaknesses (vv. 23–26). Here, however, rather than engaging in mockery, the Gentiles lack charity. Because of the allusion, we expect a continuation of the discussion about the Gentiles’ mocking relationship to the Book of Mormon. However, Moroni replaced mockery with a lack of charity. The replacement is coherent if charity means good will toward others. However, it makes less sense if we read “charity” as “love.” Possibly the Gentiles do not have sufficient love of their fellow man to accept the Book of Mormon, but then the object is man, not the weaknesses of the writing.
Moroni talks about Yahweh “proving” the Gentiles. This use of “prove” most commonly means testing that person against some command from God: “Then said the Lord unto Moses, Behold, I will rain bread from heaven for you; and the people shall go out and gather a certain rate every day, that I may prove them, whether they will walk in my law, or no” (Ex. 16:4). Yahweh commanded the Israelites to gather no more than a day’s need as a test of their faithfulness to a counterintuitive command. Here, Joseph is correctly using “prove,” borrowed from the KJV. The Book of Mormon is a test for the Gentiles and their ability to approach it without academic disdain for its weaknesses. Of course, we must study the text with all of the tools at our disposal, but we must have faith first. The scholarly study of the Book of Mormon can strengthen a faith we already have, but it cannot supply that faith. The Book of Mormon is a test for all of us, one that can turn our “weakness” for modern logic and evidence into a strong faith in this wonderful book.
Moroni then refers to the parable of the talents (Matt. 25:14–20), by warning that God will “take away their talent, yea, even that which they have received, and give unto them who shall have more abundantly.” Since the Savior had not told this parable in the New World and since it depends on conditions in first-century Palestine, this allusion cannot be Moroni’s words. The language is once again borrowed from the KJV.
Considering this analysis, I would rephrase the verse this way: “Wherefore, I know that, if the Gentiles cannot accept the Book of Mormon because of its weakness in writing, thou will find them wanting in their test of faith and will take away the blessings from them to be given to others who will be able to not only receive the Book of Mormon but also, through that book, even greater blessings.”