In "Young Goodman Brown," what evidence in the story suggests that Browns journey into the forest represents a journey into his own heart?

Goodman Brown leaves
his home one night, and he looks back at his wife, Faith. This could allegorically represent the
idea that the deeper he goes into his own heart, the more he leaves his Christian faith behind.
As he journeys within, he knows that he has an "evil purpose" and fears that the Devil
is waiting nearby. This stands in for the Christian's knowledge of temptation, of its presence,
its allure, and the inevitability that we will, at some point, give in.

As he
walks deeper and deeper into the forest, this seems to signify a dark spiritual place, a place
where the light of God cannot shine once the person chooses to enter it willingly. Brown knows
he should not go, but he chooses to do so anyway:

He had
taken a dreary road, darkened by all the gloomiest trees of the forest, which barely stood aside
to let...