What does Hawthorne say about evil in The Scarlet Letter, and how does he reflect the Christian heritage of 19th century America?
Hawthorne belonged to a group of writers called the Dark Romantics. Essentially, this group--which includes Melville and Poe--believe that mankind in basically evil, and that more often than not, his dark nature will reveal itself. Hawthorne's short stories such as "Rappaccini's Daughter," "The Birthmark," and "The Minister's Black Veil" stress this theme. So, even though The Scarlet Letter is set in the early days of Colonial America, its discussion of man's evil nature coincides with many 19th-century writers' philosophy. During the early and mid-1800s, the Dark Romantics battled with their pens against the optimists such as Emerson and Thoreau who saw the good in mankind. Hawthorne's Scarlet Letter is a clear treatise on man's soul.
Specifically, the novel through Dimmesdale, Hester, Pearl, and Chillingworth demonstrates that it is much more difficult for man to do good than it is for him to evil. What man does with his "sin" is up to him, as evidenced by Hester's redemption and Pearl's renewal/change after Dimmesdale has revealed his sin.
In regards to the Christian heritage of the 19th century (pre-Civil War), Hawthorne presents a traditional view of man's sin nature--humans are basically evil and cannot sin, hide it, and get away with it. They need forgiveness from God, confession, and true repentance in order to mature spiritually. Hester Prynne best represents the possibility for a changed life.