“And I beheld the Spirit of the Lord, that it was upon the Gentiles, and they did prosper and obtain the land for their inheritance;…
And it came to pass that I, Nephi, beheld that the Gentiles who had gone forth out of captivity did humble themselves before the Lord; and the power of the Lord was with them.”
We see here the promise given to Lehi early on in the Book of Mormon, that if he would “keep the commandments, ye shall prosper in the land” is made available to all who shall come to this land.
The Gentile nations who would come will do what the Lord had asked and would also be made to prosper in the land and put the Lamanites into submission.
The term prosper doesn’t necessarily mean just wealth. It also means having the companionship of the Holy Spirit and being able to remain in the land. (See commentary from another blogger to expound this)
Again, this promise is available to us. If we humble ourselves before the Lord and keep His commandments, we too shall be made to prosper in the land, in the due time of the Lord.