What evidence in the story suggests that Brown's journey into the forest represents a journey into his own heart? In the context, consider the significance of his fellow traveller and his wife's name.

Nathaniel Hawthorne's story "Young Goodman Brown" has several overtly supernatural elements. Its dreamlike and supernatural elements are the first clues that we should interpret the story allegorically. Our next general hint is the names of the characters. A protagonist named "Goodman" married to a wife named "Faith" suggests that the story is situated in the tradition of morality plays or allegories such as The Pilgrim's Progress, a classic work in the Puritan religious tradition which serves as the background to Hawthorne's story.
The next evidence we encounter is the prominent use of the word “heart” in the opening of the story. Faith, in the second paragraph, addresses her husband as “Dearest heart,” suggesting that her husband represents the body, mind, and heart to her, just as she represents Faith and the soul to him. Together, they constitute a complete human living in grace, but when Goodman abandons Faith, even temporarily, his heart and mind are led astray. Next, at a key transition point in the journey, when Goodman Brown overhears the Deacon and the minister, he experiences a “heavy sickness of his heart.” It is shortly after this that he appears to undergo a dramatic transformation; when he realizes that Faith appears to be part of the ungodly throng and is escaping him just as he left her, he chases after her in anguish and frenzy. In the forest, there was "nothing more frightful than the figure of Goodman Brown." This suggests that Goodman Brown, like the human heart, becomes monstrous without faith. For Hawthorne and his readers, human imperfection is grounded in original sin, handed down across generations from Adam and Eve. Thus, the fact that the “traveler,” who is likened to the Devil, takes on the appearance of Goodman’s ancestors is highly significant.
In his use of the sins of others to corrupt Goodman Brown, the Devil also suggests that the heart can lead us to damnation. Just as love for Faith can be a potential path to salvation, love or admiration for others can serve to lead us astray. If we think that those we care for are engaged in morally questionable acts, that can make us abandon hope for ourselves.