The two most important stories for understanding this novel-like short story collection are the stories "The Fire and the Hearth" and "The Old People," because in those stories, two cousins in the same family make radically different and opposite decisions about how they view their white ancestry. The first story features a man named Lucas Beauchamp, plagued with the secret knowledge that he is part black, and if anyone should ever find that out, he could be made a slave by law. "The Old People" is about one of his cousins, Isaac McCaslin, who learns a better way of life from his Native American mentor, which leads him to abandon his white privilege and heritage.
Notice that in "The Old People," Isaac is anointed by blood. This is a signal (especially to Faulkner's original readership) that this young man is a Messianic hero, meaning that his story follows the model of a religious messiah, like Jesus, for instance. The reader should consider this religious connection with merit, because after all, his name is literally Isaac (the Biblical ancestor of Jesus's whose story involves him almost being literally sacrificed to God), and because his anointment is done with blood (a signal of his sacrifice), and because in the next story, "The Bear," he rebukes his entire family and culture and voluntarily sacrifices his worldly inheritance, quite literally.
For this, sacrifice, he earns a reward. In "Delta Autumn," he meets one of the women who married into the family he walked away from. This happens as he makes his way toward death (shown metaphorically by the story taking place in autumn, and by Isaac's slow progress toward the ocean). Therefore, his reward is that his family honor is with him.
Now compare that to the first story, "The Fire and the Hearth." What is Lucas's reward for identifying so obsessively as a white person? His constant fight for money leaves him exhausted and alone, and in the end, his wife leaves him. Apparently, Faulkner appreciates Isaac's way of viewing the world over Lucas's.
