The last few chapters have been full of history, but Moroni breaks into the narrative here to teach and to issue some promises. Here are the ones I see:
Active belief in the future joys God promises will anchor our souls, making us sure and steady so that we can abound in good works and glorify God.
Through faith in Jesus Christ, we can each be partakers of the heavenly gift.
The Nephite record will come forth to their brethren through the Gentiles.
As we come unto the Lord, he will show us our weakness. And if we them humble ourselves before him, he will turn weakness into strength.
To Gentiles -- He will show us our weakness and that faith, hope and charity lead to him.
We can inherit a place in the mansions of the Father if we have hope and charity.
If we seek Jesus, the grace of God will abide in us forever.
Jerusalem will be rebuilt to the house of Israel as a holy city unto the Lord
A New Jerusalem, also a holy city, will be built in the Americas to the remnant of Joseph
The house of Joseph will built in the Americas and will no more be confounded.
There will be a new heaven and earth.
The inhabitants of the New Jerusalem will be washed white in the blood of the Lamb
The inhabitants of Jerusalem will come from the 4 quarters of the earth and the north countries and be washed in the blood of the Lamb.
Some of the first shall be last, and some of the last shall be first.
There’s a lot here, but I’m particularly struck with the promise to be “patrackers of the heavenly gift.”
What is that exactly? The first thing that comes to mind is that it is the gift of salvation, of being able to be received into heaven. And I think that's true. But perhaps there are layers of meaning to this term and an additional meaning that refers to a specific gift or talent. There might be a hint of that in Moroni's follow-up to the promise of the gift: "that they might hope for those things which they have not seen."
Ether was prophesying during a time of advanced moral decay, to a people who were nearly ripened in iniquity. So when he taught that "whoso believeth in God might with surety hope for a better world" he was teaching people who needed a better world, who encountered genuine evil in their day to day. He shared the absolute promise is that, whatever goes on around us, if we hold fast to the Lord and exercise faith in Him, we will eventually be lifted up to be with Him. But, might there also be a promise to impact the world we live in for good?
I think Ether had the gift to create a little bit of heaven in the midst of the hell that surrounded him. We don't get to hear about his family or any others that might have actually listened to his teaching, but there must have been someone who heard. Otherwise, I think he would have been silenced, like prophets before him. And we hear him now because that bit of heaven of which he wrote has been preserved for our sakes.
I think that's part of what it means to be partakers of the heavenly gift. It's not just to be able to get to heaven, but also, to be agents of heaven, to believe in the light (despite encompassing darkness) with such steadfastness and confidence in God that a glimmer of that light comes into visible form?