In Nathaniel Hawthorne's Young Goodman Brown, there are several themes that he is alluding to with his story of Brown and his journey not just into the woods, but into the nature of the human soul.
Hawthorne wrote this story very much aware of his own ancestor's unimpressive part in the Salem witch-trials. The concept of sin at every turn is very much a part of what occurred in 1692 in Massachusetts during the "witch-hunts" where the most admirable of people within this Puritan community were accused and executed.
It is not surprise then, perhaps, that Hawthorne concentrates on this same idea in Young Goodman Brown. The first point that Hawthorne is making is that of the sin of every individual. Brown, who is so quick to believe the worst in others is, himself, traveling through the woods at night—the Puritans believed the Devil inhabited the woods. Brown does not tell his wife why he is going:
“My love and my Faith,” replied young Goodman Brown, “of all nights in the year, this one night must I tarry away from thee. My journey, as thou callest it, forth and back again, must needs be done 'twixt now and sunrise..."
The second point that Hawthorne makes is that the "faithful" are unrealistic regarding the sins of others. Brown, even while he is about on questionable business, believes his ancestors were without sin:
“My father never went into the woods on such an errand, nor his father before him. We have been a race of honest men and good Christians since the days of the martyrs; and shall I be the first of the name of Brown that ever took this path..."
The old man he meets (who we assume is the Devil), however, tells him:
I have been as well acquainted with your family as with ever a one among the Puritans; and that's no trifle to say. I helped your grandfather, the constable, when he lashed the Quaker woman so smartly through the streets of Salem; and it was I that brought your father a pitch-pine knot, kindled at my own hearth, to set fire to an Indian village, in King Philip's War.
Hawthorne points out that even when faced with the news of his ancestors, Brown still is slow to believe that the people in the community that he admired could be in league with the Devil when he meets them as he travels through the forest. In fact, he is disappointed—not at all realistic:
As he spoke he pointed his staff at a female figure on the path, in whom Goodman Brown recognized a very pious and exemplary dame, who had taught him his catechism in youth, and was still his moral and spiritual adviser, jointly with the minister and Deacon Gookin...
“The devil!” screamed the pious old lady.
“Then Goody Cloyse knows her old friend?” observed the traveler, confronting her and leaning on his writhing stick.
“Ah, forsooth, and is it Your Worship indeed?” cried the good dame.
“That old woman taught me my catechism,” said the young man; and there was a world of meaning in this simple comment.
Brown sees others also approaching what seems to be a Black Mass in the woods. The last, however, is his own young wife, Faith. And this knowledge is particularly distressing to him.
Suddenly, everyone disappears. Brown cannot be sure that what he saw was true: it could have been a dream. However, the potential of evil in others (even himself) so disheartens him that he closes himself off from everyone he knows and dies alone.
Brown, thinking himself far superior to others, is the same as everyone else, but cannot see it.