In Nathaniel Hawthorne's celebrated short story "Young Goodman Brown," the protagonist leaves his young, innocent wife, Faith, to journey into the wilderness to engage in an "evil purpose." As Young Goodman Brown reluctantly travels into the forest, he is tempted by the devil to continue his journey, where he will eventually witness a "witch-meeting" or Black Mass, which is an unsettling Satanic ritual.
During Goodman Brown's journey through the wilderness, a pious old woman named Goody Cloyse interacts with the devil, and he watches as Deacon Gookin and the minister travel together to participate in the wicked ceremony.
Despite second-guessing his decision to travel through the wilderness, Goodman Brown is not able to resist temptation and succumbs to his natural human instincts, which Hawthorne suggests are universally wicked and corrupt. Hawthorne never explicitly states Goodman Brown's purpose for choosing to follow the devil into the forest, but it is implied that he wishes to experience something forbidden, which will satisfy his inherent sinful desires.
It is not necessary for the reader to know exactly what Goodman Brown is hoping to find in the forest, but it is more significant as to why he chooses to embark on his journey. Hawthorne is suggesting that all humans are inherently corrupt and will eventually succumb to temptation at some point in their lives, which is the moment they lose their innocence. One can surmise that Goodman Brown was intrigued by something forbidden and could not resist temptation, which is why he decided to abandon Faith in order to travel through the wilderness, where he eventually witnessed a Black Mass.