Come devil! For thee is this world given..." This passage reflected Goodman's surrender to the wilderness, to the state of disorder that made him discover that he is weak and sinful. The presence of Faith in the first part of the story was also the only time that Goodman felt his strong faith in God. However, upon entering the wilderness, Faith his wife had not only disappeared, but Goodman's faith in God (and even himself) as well. Hawthorne made readers realize that human nature is in fact "naturally savage," and it is only fitting that Goodman's inherently savage nature would be discovered and uncovered (by him) in the wilderness.
Even towards the end of the story, Hawthorne continued to haunt his readers with the theme of wilderness inherent in the hearts and minds of humanity. Posing the question, "Had Goodman Brown fell asleep in the forest, and only dreamed a wild dream of a witch-meeting?," Hawthorne was actually creating disorder in the minds of his readers, making them also question whether Goodman's confrontation in the wilderness was an illusion or not. This unanswered question unsettled the ending of the story, leaving Hawthorne's readers groping in the "wilderness" of interpretation, just as Goodman had been lost in the wilderness of his heart and mind.
Fitzgerald's "Great Gatsby" used a setting far less rustic and disorderly as Hawthorne's wilderness in "Young Goodman Brown." Fitzgerald's portrayal of the wilderness in his novel was the harshness of society towards individuals who deviate from its standards of conformity in terms of beliefs and values in life. Wilderness is metaphorically portrayed between the conflicting natures of the East Egg and West Egg regions of New York City. Social inequality was the dilemma presented in the novel, a problem in the American society that reflected how, despite the improvement in civilization, humanity did not leave its savage nature. Savagery is mirrored in the conflict between the old rich and "noveau riche" members of the society -- people from the East and West Egg regions, respectively.
The wilderness (social conflict) in the civilized natures of both regions was explicated by Nick in the novel, where he stated, "I lived at West Egg, the -- well, the less fashionable of the two, though this is a most superficial tag to express the bizarre and not a little sinister contrast between them." This interesting observation by Nick showed how, despite the seemingly more sophisticated nature of the East Egg residents, they are actually part of the 'urban wilderness' of the city, where disorder originated from their intolerance to individuals who were able to go up the social ladder, achieving the level or even surpassing the 'old riches' people of the society.
Intolerance to the new rich-people in the West Egg was embodied in the character of Gatsby, whose sudden appearance in the high society of New York led to the dissemination of rumors and hostility against him and everything he stands for (i.e., the success of the new rich-people in urban societies). Wilderness is portrayed through the inability of the New Yorkers to show 'civilized behavior' despite the improvement of the standards of living of people in the modern period. This was reflected in the characters of Tom and Daisy, who fervently expressed their disagreement to the rise of the new rich-people: "It's up to us, who are the dominant race, to watch out or these other races will have control of things... We've got to beat them down." The rise of urbanism displaced the role of nature in the city, but the existence of a metaphorical wilderness still exists. Fitzgerald's novel was an attempt to inform his readers about the inherent need of humans to seek conflict, instability, and disorder even though human society already went through remarkable social and intellectual progress.
In sum, literal and metaphorical wilderness in "Young Goodman Brown" and "Great Gatsby," respectively, were used by Hawthorne and Fitzgerald in order to show how the protagonists confronted their inner selves -- the true feelings and thoughts of the individual and confronting the 'inner savage' dwelling within the hearts and minds of Goodman and the urban society of New York City.
Fitzgerald, S.F. E-text of "The Great Gatsby." Project Gutenberg of Australia Web site. Available at http://www.gutenberg.net.au/0200041.txt.
Hawthorne, N. E-text of "Young Goodman Brown." Available at http://unx1.shsu.edu/~eng_wpf/authors/Hawthorne/Goodman-Brown.htm.