After Mormon tells Moroni the awful details of the wickedness among the Nephites and Lamanites, he ends his letter by blessing Moroni in an interesting way:
And may the grace of God the Father, whose throne is high in the heavens, and our Lord Jesus Christ, who sitteth on the right hand of his power, until all things shall become subject unto him, be, and abide with you forever. Amen. (Moroni 9:26)
This can be difficult to parse because of a gigantic dependent clause stuck between the subject and the verb in the sentence. What it essentially says is, “may the grace of God the Father… and our Lord Jesus Christ …be, and abide with you forever.” Be strong in God and Christ.
So what is that middle stuff trying to say? “God the Father, whose throne is high in the heavens, and our Lord Jesus Christ, who sitteth on the right hand of his power, until all things shall become subject unto him..”
Again, Mormon has just finished telling Moroni a number of awful ways the Nephites are disobeying his [Mormon’s] authority as preacher, as general, as apostle, as testifier of Christ. The Nephites are without order and don’t listen to authority, so it is comforting to Mormon that God and Christ rule in the heavens, and even if Mormon can’t enforce his commands, God can enforce His. And even if all Mormon’s society and his enemies are determined to defy God, it can’t and won’t last because eventually Christ will subject all things to Him.
It’s a comfort for today as well. Even if the world seems determined to tread Christ and the commandments under their feet, it can’t last because God and Christ do rule in the heavens, and someday every knee shall bow and every tongue confess their authority. The best we can do is subject ourselves to them as soon as possible.