Reverend Hooper’s black veil could be read as an allusion to the following verse from the Bible: “For now we see through a glass, darkly; but then face to face: now I know in part, but then shall I know even as I am also known” (1 Corinthians 13:12).
This verse expresses the idea that, while on Earth, one cannot fully know God. Hawthorne's allusion suggests that, likewise, one cannot know people, not even the people that are closest to them—one can only know them “in part.” This is because life on Earth, according to this verse, isn’t the ultimate reality; it is only in eternity, after death, that a person can see the full truth of things. Reverend Hooper wears his black veil as an outward expression of this idea: he wants to show that everyone is barred from truly knowing one another while alive, and so he wears a black veil to literalize what he sees as the “veil” of appearances people are always wearing, obscuring the truth of their soul beneath.
Reverend Hooper expresses this idea to his fiancée, Elizabeth, after she begs him to take off the veil for her sake. He reassures her that the veil is only temporary, and that, while she may not see his face while they are alive, she will be able to see his true face when both of them are dead and in Heaven:
“There is an hour to come," said he, “when all of us shall cast aside our veils. Take it not amiss, beloved friend, if I wear this piece of crape till then.”
Then later, he begs her to stay with him:
“Have patience with me, Elizabeth!” cried he, passionately. “Do not desert me, though this veil must be between us here on earth. Be mine, and hereafter there shall be no veil over my face, no darkness between our souls! It is but a mortal veil—it is not for eternity! O! you know not how lonely I am, and how frightened, to be alone behind my black veil. Do not leave me in this miserable obscurity forever!”
The veil being black in color further supports the idea that it is an allusion to “through a glass, darkly.” He is still able to see the people around him, but they are hazy and blurred, given a darkened aspect by the black color of the fabric. However, the townspeople of Milford are made uncomfortable by Reverend Hooper’s choice to cover his face. For Reverend Hooper, wearing the black veil actually makes him feel closer to the people around him, because in his view, surface appearances are illusory and distract from spiritual truth. But for Elizabeth and the townspeople, who rely on surface appearances to make moral judgments about others, the veil has a distancing effect that frustrates efforts to understand one another.