The influx of Gadiantons and their foreign ideas and gods causes the Nephites “to dwindle in unbelief.” That phrase, “dwindle in unbelief” is used several times in the Book of Mormon. In the book of Nephi, it is typically in the context of the predictions of the future of the children of Lehi, and in particular, the destruction of the Nephites. Thus, when these Nephites” begin to dwindle in unbelief,” we may be certain that something bad is coming. Indeed, there will be a complete destruction of the Nephite government prior to the arrival of the Savior in Bountiful.
There is a contrast, however. There are righteous Lamanites. The blessings of the Lord are not exclusive to Nephites. Any who obey the covenants has access to the covenant promise of the land.