An ardent believer in the moral sanctity of his soul, Arthur Dimmesdale surrendered sexually to Hester Prynne, a wife of Roger Chillingworth. This act of sexual surrender created an excruciatingly painful guilt on the part of Arthur Dimmesdale. The notion that he is a sinner, that he committed adultery, that he should have been chaste, that there is no outlet for his moral crime – collectively haunted him. To penance his moral crime the minister punished himself. He confined himself in his room and indulged in self-punishment. The more he punished himself the guiltier he felt. He gradually suffered from psychological isolation. On the other hand, Hester Prynne was publicly chastised and punished according to the standard of the puritan moral law. She did not feel ashamed of the crime of adultery, she happened to commit on the spur of the moment. As a token of punishment she was forced to wear a scarlet letter. She was socially ostracized. She was compelled to live in isolation with her daughter, Pearl. As Pearl grows older, her behavior strikes the townspeople and at times, Hester herself as strange and unnatural. But when the townspeople try to have Pearl removed from Hester's care, the anxious mother visits governor Bellingham's home, hoping to enlist his help. During the visit, Pearl comes into contact with the Reverend Arthur Dimmesdale, her father, though she has ever been told this. The usually hard- hearted child is tenderly attracted to Dimmesdale, a fact that does not go unnoticed by Roger Chillingworth, who has been acting as Dimmesdale's personal physician. One night Dimmesdale returns to the scaffold where, years earlier, Hester and Pearl had stood alone. Plagued with guilt, he mounts the stand; Hester and Pearl join him there. Pearl asks him to stand with them again tomorrow in public view, but he refuses.
Hester plans to reveal to him that Chillingworth, Dimmesdale's physician, is in fact her husband. One day she tells Chillingworth that she must reveal his identity to Dimmesdale, and begs him to forgive the man. Chillingworth counters by saying that a higher power than himself is controlling his actions. Convinced now that Chillingworth will prove to be the end of Dimmesdale, Hester intercepts her love in the forest and reveals to him that Chillingworth is her husband. She further declares that her husband is intent on ruining Dimmesdale and urges him to escape the doctor's evil eye. Excited by thought of escaping to Europe with Hester and Pearl, Dimmesdale returns to town light of heart and full of reckless impulses. He is tempted to utter blasphemy (disrespect to God) and in one instance, to speak obscenely to a young girl, Frightened by this sudden change in himself, he runs in to Mistress Hibbins, who has long been suspected of being of witch. Mockingly, she questions him about his trip through the forest and laughs when he attempts to deny any wrongdoing. Returning to his room, he fears that he may have sold his soul to the devil. Dimmesdale burns the sermon that he had intended to give during the ceremonies making the election of a new governor and, instead, stays up all night to draft another.
Hester is horrified to learn that Chillingworth has booked passage on the same ship, she was planning to take to Europe with Dimmesdale and Pearl. As she laments this turn of events, she warns Pearl not to accept Dimmesdale to acknowledge their presence in public, throughout the novel, there is the suggestion that Pearl knows who her father is, but Hawthorne leaves it ambiguous at this point. Hester warns her daughter only that their friend the minister might not what to recognize them. But after delivering a brilliant sermon, Dimmesdale stumbles out of the Church with the procession. He stops at the scaffolding, where he summons Hester and Pearl to join him. Chillingworth follows, a party to the sin because of the emotional torment he has visited on Dimmesdale. Ascending the scaffold, Dimmesdale escapes Chillingworth's evil clutches by admitting to the crowd that he is Pearl's father. Declaring that everyone should now witness the symbol of his sin, he exposes his bare chest to reveal as witness the symbol of his sin, later insist-a scarlet A 'imprinted in the flesh'. Following this revelation, Dimmesdale collapses and dies in Hester's arms.
In a nutshell, The Scarlet Letter is a depiction of puritan society where a priest was not expected to be in love with anyone and adultery was regarded a great sin.