1 Nephi 22

1 Nephi 22: 8, 9

And after our seed is scattered the Lord God will proceed to do a marvelous work among the Gentiles, which shall be of great worth unto our seed; wherefore, it is likened unto their being nourished by the Gentiles and being carried in their arms and upon their shoulders. And it shall also be of worth unto the Gentiles; and not only unto the Gentiles but unto all the house of Israel, unto the making known of the covenants of the Father of heaven unto Abraham, saying: In thy seed shall all the kindreds of the earth be blessed.

OK so when I read this I pretty much felt like it is referring to temple work. First because in our time God has made known unto us the covenants that he made with Abraham and we make the same covenants in the temple. When we are sealed to our spouse or family in the temple we make the same covenant that if we are faithful we will have an endless increase.

But specifically this scripture refers to the part of the Abrahamic covenant where God promised Abraham that through his seed all of the nations of the earth would be blessed. I think most of the time that is seen as referring to Jesus, which fits because he came through Abraham's seed and he blessed all the families and people of the earth through his atonement. However this scripture is referring to a great and marvelous work that will be done after the time of Christ. I think that this is again referring to temples. In the temple we work vicariously for all of the people that have ever lived on this earth. All families of the earth will be sealed together for eternity creating an unbroken chain from Adam to our day. Essentially, individual families will be sealed together but also the entire human family will be connected, in a literal and spiritual way, through the power of the priesthood. We will all be gathered into one family, with one Father in heaven. And it will be brought to pass through the seed of Abraham, this is part of the covenant. Hence the churches mission to preach the gospel and to redeem the dead.