It may seem at the outset that these are conflicting concepts, and, perhaps in the dictionary sense, that may be true. What do we do when this happens? Do we dismiss efforts to explain them? I think doing so is a serious mistake.
Words do matter. And it's difficult when words seem to get in the way of our understanding or communication. But when we are using words in the gospel (or even in relationships), we are seeking to explain and understand concepts that have an eternal (or at least a concealed) dimension (in relationships, we rarely know all that is behind the words said or written (experience, upbringing, pain, motives, etc.). As such, words themselves will usually not be sufficient to truly understand gospel concepts, or to understand each other. If we limit ourselves to only words, and react only at the level of dictionary definitions (or our limited, I believe we will miss significant opportunities for meaning and understanding, and also for compassion.
In fact, I believe we have a solemn responsibility to receive words with more than just dictionary in hand. We must receive by the Spirit.
I was reminded today of Moroni in Ether 12. Imagine the weight of knowing your words would be passed down for generations, and would be an anchor for gospel teaching. He laments the limitations of language, of his words. He goes to the Lord in fear and concern:
"[W]hen we write we behold our weakness, and stumble because of the placing of our words; and I fear lest the Gentiles shall mock at our words" (v. 25).
The Lord comforts him by letting him know that the listeners (readers) have a responsibility to receive the words in the right spirit.
"And when I had said this, the Lord spake unto me, saying: Fools mock, but they shall mourn; and my grace is sufficient for the meek, that they shall take no advantage of your weakness..." (v. 26).
Do we ever take advantage of the apparent weakness of others' words? I fear that too often we do, be they words from prophets or even just from those around us in our day-to-day lives. We insist that the way we understand what they said is correct. We hold up dictionaries and worldly learning and our own experiences alone, and thus too often feel justified in criticizing or dismissing or undermining or reacting unkindly to what their words. (Misunderstandings, after all, are just about misunderstanding words, right? We all know this happens far too often in our lives and relationships. We know it also happens in the Church.)
It seems to me that the Lord expects more of us, however. This is evident in these verses in Ether 12. I think we also find warnings against such reactions to words in 2 Nephi 28:
...And there shall also be many which shall say: Eat, drink, and be merry; nevertheless, fear God--he will justify in committing a little sin; yea, lie a little, take the advantage of one because of his words, dig a pit for thy neighbor; there is no harm in this
Other scriptures also recognize the limitations of language (see, for example, 3 Nephi 5:18)
I think of a wonderful talk by A. Roger Merrill in last year's October General Conference. He talked about receiving by the Spirit. I believe that as we receive by the Spirit, with meekness and charity, the Lord will magnify seemingly weak words and help us understand things that our minds alone cannot understand. He will also overcome our weak tendency to take advantage of others because of their words, or their weakness. The Lord's grace is sufficient for us, and for them. It is our opportunity and responsibility to tap into that grace or I believe we will mourn as we someday discover that we have missed opportunities for spiritual understanding and experiences with gift of charity.
Indeed, words matter, but I believe grace and charity matter more.