The theme of sin develops throughout the book by starting off as the main theme that causes Hester to wear the scarlet letter...
and continues to develop as Dimmesdale cannot come to confess his sin of being her lover. Near the end of the book, Hester's sin starts to fade away..
and she is no longer looked down upon for her sins but is loved for her help within their community.
Another them, of the two different types of guilt, develops throughout this story. Hester is the prime example of public guilt because she confesses her sin..
and wears the A so the whole town knows. Dimmesdale, the prime example of private guilt, does not confess his sin..