Though much of "The Minister's Black Veil" actually focuses on what unites humanity -- our inherently sinful natures as well as our universal attempt to hide our true natures from others -- Mr. Hooper emerges as the sole individual in his parish who is willing to acknowledge this truth.
Although his congregation is uncomfortable with the veil from the moment they first see Mr. Hooper wearing it, it is not until after his first sermon that they begin to understand what it signifies.
The subject [of the sermon] had reference to secret sin, and those sad mysteries which we hide from our nearest and dearest, and would fain conceal from our own consciousness, even forgetting that the Omniscient can detect them.
At this point, each listener "felt as if the preacher had crept upon them, behind his awful veil, and discovered their hoarded iniquity of deed or thought [...] and [they] quaked." After this, Mr. Hooper's "courtesy" was repaid with "Strange and bewildered looks," and he no longer receives his traditional Sunday-dinner invitations. His congregation, uniformly, chooses to disregard the truth of what Mr. Hooper has said, the truth of the symbol of the veil, and to believe, instead, that "'Something [is] surely [...] amiss with [his] intellects.'" It is, as Mr. Hooper points out, easier to put this truth out of mind; we cannot even bear to think of ourselves as secret sinners let alone to tell others it is so. He is, in short, the only individual who is willing to own up to it. Mr. Hooper is brave enough to tell the world that he has secret sins that he tries to hide, and no one else has this courage. Even his fiancee, Elizabeth, when she realizes what the veil symbolizes and understands that he will always wear it (in life), is unwilling to stay with him because she will not be able to bear the reminder of her own soul's stain.
Mr. Hooper is a true individual, willing to say and do things that might be unpopular and make other people uncomfortable for the sake of being true to himself.