" 'Poor little Faith!' thought he, for his heart smote him. 'What a wretch am I, to leave her on such an errand! She talks of dreams, too. Methought, as she spoke, there was trouble in her face, as if a dream had warned her what work is to be done tonight. But, no, no! 'twould kill her to think it. Well; she's a blessed angel on earth; and after this one night, I'll cling to her skirts and follow her to Heaven.' "
This ability of the narrator is why the story has a limited point of view, since it does not apply to other characters in the story.
The narrator is an intrusive one who evaluates and comments on the actions and motives of the characters. When Goodman resolves to make this the last time that he ever does such a thing, the narrator evaluates his resolution:
" 'Well; she's a blessed angel on earth; and after this one night, I'll cling to her skirts and follow her to Heaven.'
With this excellent resolve for the future, Goodman Brown felt himself justified in making more haste on his present evil purpose."
This point of view gives Hawthorne much more flexibility than a regular third-person narration. A regular third-person narration would leave no chance to add the commentary to the action. Additionally, it leaves him with the ability to drop in his own thoughts on mankind.