should be so bitter about it.

Whether he's justified in being this way is a different matter. One can certainly understand Brown's feeling the way he does towards people, including his wife, who he once thought to be good, God-fearing folk. But one could argue that he only has himself to blame for being so naive about human nature in the first place. Brown's little world appears to be black and white, without any shades of gray. So when he sees all those supposedly respectable people cavorting in the forest one night, his instinctive reaction is to separate himself from the common lot of humanity and maintain a constantly suspicious attitude toward those around him.

Young Goodman Brown reacts very coldly toward his wife and the people in his town after he's returned from his strange trip into the woods.

Why does he react strangely? He believes that he's seen pretty much everyone he knows -- including the most virtuous old woman of his town, the one who taught him his catechism  -- on their way to or participating in the satanic mass in the forest.

Is he justified in acting this way? If what Young Goodman Brown saw was the truth -- that is to say, if he indeed witnessed all of his neighbors engaged in devil worship -- then maybe yes, he would be justified in maintaining cool relations with them. The narrator, however, adds more than a few terms -- such as "seems like" and "as if" -- in order to suggest very strongly that what Young Goodman Brown thinks he witnessed did not actually happen.

At the start of "Young Goodman Brown," Goodman Brown is very much in love with his new wife, Faith. She is pretty, affectionate, and seemingly innocent. Goodman projects a lot of his religious and moral ideals onto Faith. He sees her as angelic, proof that pure goodness exists in the world.

Goodman's experiences in the woods dramatically change the way he sees other people, especially his wife. When he sees her among the devil-worshiping congregation, he loses his faith in goodness. Instead of accepting that good and evil commingle in every soul, he decides that evil's existence blots out any and all good in everyone.

When he returns to the village, he rebuffs Faith's joyous greeting and attempt to kiss him. He comes to see her as a contaminated sinner, just like all the other Puritans in the town. The text only gives the reader one sentence describing Goodman and Faith's future married life, but it is a potent one:

Often, waking suddenly at midnight, he shrank from the bosom of Faith; and at morning or eventide, when the family knelt down at prayer, he scowled and muttered to himself, and gazed sternly at his wife, and turned away.

Ultimately, the marriage becomes a miserable one, with Goodman going from ardent lover to stern judge toward Faith overnight. Regardless, Faith appears to continue to be loyal to Goodman, dutifully following his body to its grave after he dies a miserable old man.

More specifically, he shrinks away from the blessings of the minister. He grabs a child away from Goody Cloyse as she is teaching her the catechism, he refuses to greet his wife Faith, and he worries and wonders as he sits in church for the rest of his life why the roof does not cave in every time a prayer is said or a hymn sung. He becomes solitary and despairing, a man who has become disillusioned with the one thing he had proudly built his life around, his faith.

When Young Goodman Brown returns from his experience in the forest--whether that experience was real or a dream vision--he is a changed man.  He left the village the night before as a typical young married man in his village, full of life and with a pretty wife named Faith.  Unfortunately, on his return his attitude toward the people of his village, as well as his wife, was completely changed--fearful, suspicious, and, more important, perceiving evil in everyone around him:

[when Goodman Brown passes his minister] He shrank from the venerable saint as if to avoid an anathema [a curse].

Goodman Brown saw, or thought he saw, his minister,  Deacon Gookin, Goody Cloyse (the woman who gave him religious instruction) in the forest communing with the devil, so when he sees Goody Cloyse teaching a young girl her catechism, "Brown snatched away the child as from the grasp of the fiend. . . ."  Clearly, the evil that Young Goodman Brown perceived in himself, which caused him to go into the forest at night, he sees in everyone else he once thought were good religious people.

Even Faith, whom he knows better than all the others and who tries to kiss him when she sees him in the morning after the visit to the forest, is given a cold welcome: "But Goodman Brown looked sternly and sadly into her face, and passed on without a greeting."  Brown undoubtedly justifies this behavior to himself because he saw Faith with the others at the devil's meeting place.

To determine whether Young Goodman Brown's behavior is justified you have to decide if you believe one of two things: 1) Did Young Goodman Brown journey into the forest, meet the devil, and see all of the religious people from his village, including Faith, at the satanic ceremony? or 2) Did Brown, perhaps because of his own sense of guilt for having inappropriate thoughts, have a dream or vision in the forest?  If you believe in (1), then you can argue that his behavior is justifiable, having been betrayed by everyone he thought he knew.  On the other hand, if (2) seems more likely to reflect what actually happened to Brown, then you have to argue that Brown's sense of guilt has altered his ability to perceive reality as it is.  I would vote for (2).