Define “sin” as it is set forth in The Scarlet Letter.Nathaniel Hawthorne's The Scarlet Letter

Nathaniel Hawthorne's novel, The Scarlet
Letter, has its theme centered uponthe Puritan theology.  Within the Puritan
community in which Hester Prynne and Arthur Dimmesdale live, Adam and Eve's sin
parallels that of Hester and the minister.  For, in both cases, their sins effect
expulsion and bring about knowledge of what it means to be human.  The Puritans believed
that all humans felt the effects of Adam and Eve's sin, but there was an "elect" who
were chosen to be saved.  However, it was difficult to know if one were saved or damned;
therefore, the Puritans tried to behave in an exemplary manner although a superiority of
faith exceeds any good works that one performs.

Oddly
enough, however, although the Puritan theology admits no redemption by good works,
Hester, who aids the sick and elderly comes to be viewed much more positively than
before when the emblem of her sin of adultery has been placed upon her bosom.  New
interpretations of the A come into being; some say it stands for
"Able"; others perceive the letter as representing "Angel."  And, with her performance
of charitable works, Hester attains some degree of redemption, and, certainly, she is
given passage into regions where other women are not allowed, thus permitting her to
think of herself more boldly as she does in Chapter XIII.  On the other hand, because
Dimmesdale keeps his sin secret from fear of condemnation and expulsion by the Puritan
community, his sin becomes a great burden to him.  Yet, it affords him an empathy for
his fellow man which, ironically, endears him to the congregation.  Decidedly, Hester
and the Reverend Dimmesdale both essay to reconcile their sins with their experiences. 
These actions indicate  Hawthorne's disapproval of Puritanism as in the end he calls to
all to

"Be
true! Be true! Show freely to the world, if not your worst, yet some trait whereby the
worst may be inferred!" 

Of
course, it is the hypocrisy attached to secret sin that Hawthorne most strongly
attacks.  In Roger Chillingworth, evil is truly found in his heart.  Whereas the sin of
Hester and Arthur Dimmesdale is one made in love, Chillingworth's actions are driven by
hatred and a desire for revenge, the antithesis of love.  Thus, he is the greatest
sinner of all, as Dimmesdale does repent before he falls and dies on the
scaffold. 

Conclusively, while the Puritans insisted on the
perception of sin as an obstacle on the path to heaven, Hawthorne calls to all to reveal
their secret sins and atone, for through confession and atonement one achieves
redemption--a very unPuritan precept.