Mormon 7 is a letter from a dying prophet to the modern day descendants of his people. It's full of both promises and exhortations and I'm going to list them all, with promises in bold.
You are of the house of Israel
You need to repent or you can't be saved
Lay down your weapons of war, swear off bloodlust, and don't take up arms again unless commanded by God.
Learn of your fathers, repent of your sins, and believe in Jesus Christ, his victory over death, and the resurrection and judgement he brings about.
Jesus has redeemed the world so that all cleansed in him can dwell with God in endless happiness
Repent, be baptized in his name, and lay hold on his gospel set out in the Bible and Book of Mormon, which testify of each other and identify your ancestry and legacy of faith.
Receive also the baptism of fire, follow the example of our Savior, and it shall be well with you.
I'm trying to place this message into the context of time. There are a bunch of thoughts that occur to me.
Verse three is kind of puzzling. I'm reading this message as being directed at the First Nations people today, but I'm not aware of their having weapons of war taken up. At least, not the First Nations people in my geographical area. But there's plenty of armed unrest right now in Central America. Also, the Book of Mormon originally came forth at a time when the white settlers and the Native Americans were in a state of ongoing war. So, this exhortation could apply to that time and to the ongoing conflicts in Central and South America. It could also apply to a future outbreak of armed conflict here -- a scary prospect that becomes increasingly imaginable as civil unrest spreads across North America. I keep reading the Lord's warnings to the Gentiles to repent or the House of Jacob will go through among us as a lion among sheep as presenting that possibility and instructing us on how to avoid it.
Another thought. I keep forgetting the enormity of the family of Lehi. While the Church does not have a doctrinal position on the precise modern identity of Lehi's descendants, Joseph Smith and the early Brethren seem to have counted the indigenous peoples of North and South America among them. In addition, the Maoris of New Zealand and the Polynesians have been repeatedly identified as the people of Hagoth, a Nephite ship-builder and explorer.
This is not to claim that these modern populations descend exclusively or even predominantly from Lehi. It seems that one of the Lord's established strategies to bless all his children is to scatter Israel among them so that blood lines mix and all the families of the earth become heirs to the promises made to Abraham. It seems likely that the Lord employed a similar strategy with the descendants of Lehi and other early inhabitants of the ancient Americas.
What is clear to me is that the Lord is not finished his work with the descendants of Lehi. Not even close. It will be brought to pass and there will be a glorious peace and harmony in the end. It might be messy in the meantime. I am commissioned to assist with the Lord's work, insofar as I myself repent and pursue humility. If I don't, I could be on the wrong of wrenching conflicts that may be ahead.