In Hawthorne's The Scarlet Letter, there are four characters that develop and change throughout the novel.
Hester Prynne is found guilty of adultery, though she never names the man with whom she committed adultery—who fathered her daughter, Pearl. When Hester is first found to be guilty, she wears the "A" on her dress and quietly suffers being ostracized from the circle of her Puritan community. At one point, when she meets Dimmesdale in the woods, she removes the scarlet letter feeling the need to be free of it. However, by the end of the story—years after she has taken Pearl away—Hester returns. She has become accustomed to the letter. She is accepted once again within the community, known for her charitable works. The "A," which was once a punishment almost too heavy to bear, has become a part of who she is, and she has made peace with it.
She had returned, therefore, and resumed,—of her own free will...—resumed the symbol of which we have related so dark a tale. Never did it quit her bosom.
It is noted that after so long, the letter was no longer a stigma. She was no longer scorned or criticized. Hester had led such a penitent and unselfish life in the community, that the "A" eventually inspired "awe" and "reverence." People admired her, and many women came to her to share their sorrows and look for guidance. Hester bore them no ill-will.
Pearl is described in critiques of the novel as a one-dimensional character that calls for penitent behavior from her mother (when she refuses to let her take off the "A" in the woods), and chastises Dimmesdale for not exposing his part in the affair with Hester. In these situations, Pearl...
...becomes the figure of authority.
Old beyond her years, Pearl does not take on the true nature of a loving, fully developed character until Dimmesdale exposes his sins of adultery and hypocrisy on the scaffold.
Pearl kissed [Dimmesdale's] lips. A spell was broken. The great scene of grief...had developed all her sympathies; and as her tears fell upon her father's cheek, they were a pledge that she would grow up amid joy and sorrow...but be a woman in it.
Roger Chillingworth, who is Hester's husband, pretending to be a physician for most of the novel (acting as a stranger to Hester) has done everything possible to destroy Dimmesdale, not only physically, but also by poisoning the minister's heart and mind out of revenge. When Dimmesdale confesses, old Chillingworth's twisted satisfaction in tormenting Dimmesdale ends, for the truth is out. Dimmesdale condemns Chillingworth also as a sinner, as he lies dying. After the preacher's death, the old man changes:
All his strength and energy—all his vital and intellectual force—seemed at once to desert him...he withered up, shrivelled away, and almost vanished from mortal sight.
Once wielding enough power to break the gentle but weak-spirited Dimmesdale, Chillingworth becomes a victim of his own poisonous nature.
...there was no more Devil's work on earth for him to do...
...and Roger is lost. He dies within a year of Dimmesdale's passing.
Dimmesdale has been a man too weak to admit to his sins; he hypocritically chastised others from the pulpit for their sins, even as he suffered torment and guilt. On the night of his death, he finds grace enough to publically acknowledge his sins and pray for forgiveness, finally assuming responsibility for his actions—joining Hester and Pearl on the scaffold—redeemed and at peace.