Nephi sees and laments the eventual destruction of his people. There are two images in this verse that deserve comment. The first is that “they sell themselves for naught.” In this image, Nephi emphasizes the choice of the people. That is, their destruction does not come upon them from the outside (though that is literally true) but rather from within (the spiritual cause). In Nephi’s terms, they have sold themselves, they have exchanged their collective “soul” for something. That something Nephi calls their “pride and their foolishness.” The Book of Mormon is consistent in chronicling the cycle of pride and humility the Nephites follow. The pride is always related to the accommodations of the Nephites to the world around them. The accumulation of wealth is the part of the cycle, but not necessarily the cause. As Nephi rightly foresees, it is that in the accumulation of wealth, they sell something even more precious - their integrity before the Lord.
Once the accumulation of wealth and power begins, it begins to be defined in terms of the what the Nephites see as wealth and power around them. The acquisition becomes one not for need, but for the trappings associated with wealth and power in other peoples. Thus they sell their religious principles for the philosophies of the world around them. The sad thing is that the sale works, and that they are able to “buy” the world. As Nephi also predicts, it is an exchange of value for something of no value, because it will eventually cost them everything.
The second image in this sentence is the contrast of darkness and light. Perhaps Nephi is highlighting a theme from the cited passages of Isaiah:
Isa. 5:20
20 ¶ Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter!
Isa. 9:2
2 The people that walked in darkness have seen a great light: they that dwell in the land of the shadow of death, upon them hath the light shined.
The contrast between light and darkness is a constant image relating light to God and darkness to all that is opposed to God’s ways. This dichotomy of light and dark also leads to the doctrine of choice between life and death, which also become integrated into the light/dark imagery. While Nephi may be highlighting language from Isaiah, the concept of choosing the works of darkness, and thus being consigned to hell clearly reflects Lehi’s teaching:
2 Ne. 2:27
27 Wherefore, men are free according to the flesh; and all things are given them which are expedient unto man. And they are free to choose liberty and eternal life, through the great Mediator of all men, or to choose captivity and death, according to the captivity and power of the devil; for he seeketh that all men might be miserable like unto himself.
2 Nephi 26:11
11 For the Spirit of the Lord will not always strive with man. And when the Spirit ceaseth to strive with man then cometh speedy destruction, and this grieveth my soul.
Because this verse is the necessary conclusion to Nephi’s vision of his people’s destruction, it highlights the negative aspect of the struggle of the Spirit with wayward man. There will come a time when the Spirit that so valiantly struggles to bring us to repentance will be cease that struggle. Nephi’s conclusion is that when that Spirit that is supporting us is finally withdrawn, the end comes rapidly - perhaps because we are left to the course we are choosing, rather than being restrained by the spirit.
In Nephi’s presentation of this vision of the future, the language of the spirit withdrawing becomes the precipitator of the destruction. While this is correct, it also may leave the impression that the Spirit will tire of us, that it will be the Spirit that decides we are no longer worth saving. That is not Nephi’s intent, and it not the way the Spirit works with us. It is we who become unable to hear or feel the Spirit. Nephi earlier taught this very principle to Laman and Lemuel:
1 Ne. 17:45
45 Ye are swift to do iniquity but slow to remember the Lord your God. Ye have seen an angel, and he spake unto you; yea, ye have heard his voice from time to time; and he hath spoken unto you in a still small voice, but ye were past feeling, that ye could not feel his words; wherefore, he has spoken unto you like unto the voice of thunder, which did cause the earth to shake as if it were to divide asunder.
Those are the conditions under which the Spirit will cease to strive with us. It will be our choices that lead to the separation, not that the Spirit will finally give up on us. We may be certain that the Spirit will always be there when we come to the brink of repentance.