The culminating plea of Jacob's discourse suggests that the balance of righteousness will swing to the Lamanites resulting in skins "whiter than yours". This again suggests that the coloration of the skin has become symbolic of sin and unrighteousness, rather like the staining of garments with sin is a symbol. This visible symbol to which the Nephites have attached meaning can therefore be used to contrast the righteous states of the two. Notice that no matter how evil the Nephites become, their skin will not darken, but rather the increasing righteousness of the Lamanites will make their skin "whiter than yours." This is a cultural symbolic meaning laid over an apparent "mark" of a darker skin. This darker skin can easily have come through lifestyle (just as "filthiness" is more likely related to lifestyle that righteousness in Jacob's discourse).