Your word implications is an interesting choice. For, the suggested meanings of the journey into the forest are ambiguous since, as the previous response so aptly states, the reader does not know if Goodman Brown actually has gone into the forest. Perhaps, then, what is implicated, or inferred, is that the forest is the dark region of the heart, the flawed part of everyman's heart that entertains the idea of evil and sin. In order to assure himself of his perceptions of his wife and others, Goodman Brown must face this dark side. When he enters the forest, or darkness of his own heart, he emerges as one who has lost his faith in goodness, since he, like Kurtz in Joseph Conrad''s "Heart of Darkness" has seen "the horror!" as love and sin seek possession of his soul.
The most important symbol is the forest itself. In part because it was the home of the Indians, in part because it was a dark pathless place, it is symbolically the home of the devil. Brown must go on the journey into the forest just as we all must when we discover that the world and the people in it are not as perfect as we might think of them when we are young. Sometimes we see this when we find that our parents are just people, not perfect; sometimes it is some other adult in our life. We do not elect to take this trip; we have to. Brown tells his wife that he is going to leave her on this initiation just this one life, and then he will be with her forever; sadly, although he is with her, he is not the same man.
Of course, we do not know if Brown ever actually went into the woods or whether the whole evening was just a dream. But it doesn't make any difference because he was not able to accept the "evil" he though he saw in those closest to him.
In the story "Young Goodman Brown" when Brown goes into the forest, “Hawthorne emphasizes the split between convention and the unconscious by having Brown move from the town to the country as he follows his impulses. The deeper he moves into the forest, the more completely he becomes one with his ‘evil’” (Bunge 13). The forest is evil and the act of going into the forest is an act of faith. Brown feels he can remain faithful to who he is, yet the farther he goes the more he becomes in-touch with that darkness in all of us.