What is the topic of the first sermon Mr.Hooper gives while wearing the veil?

Mr. Hoopers
first sermon in The Ministers Black Veil is about the notion of guilt or secret sin, a
familiar idea in Hawthornes work. Hawthorne establishes this theme early on with the minute
details that set the scenespecifically, the gossip amongst the villagers and their speculations
as to the meaning or significance of the black veil. Their varied remarks essentially pass a
kind of judgment upon Mr. Hooper. Notice that Hawthorne does not directly quote the specific
words Mr. Hooper delivers during the first sermon; rather, Hawthorne uses description to convey
an ominous mood within the meeting-house as the omniscient narrator marks the theme of secret
sin using Mr. Hoopers congregation:

A subtle power was
breathed into his words. Each member of the congregation, the most innocent girl, and the man of
hardened breast, felt as if the preacher had crept upon them, behind his awful veil, and
discovered their hoarded iniquity of deed or thought. (Hawthorne 1313)

The mystery of the veil and Mr. Hoopers motivation for wearing it
reflect a tendency toward ambiguity in Hawthornes writing. Here, as in many of the tales
(Hawthorne tended to refer to his shortas tales instead of short stories), the ambiguity
also helps to communicate the notion of secrecy, of something dark and sinister, as it
were.

Work Cited:

Hawthorne,
Nathaniel. The Ministers Black Veil. The Norton Anthology of American
Literature, 7th ed., edited by Nina Baym, Robert S. Levine, and Arnold
Krupat, vol. B, Norton, 2007, pp. 1311-1320.