Contrary to what a reader may initially assume from the title of the novel and the opening chapter, Hawthorne indicates in his narrative that Hester's sin of adultery is not the most grievous of transgressions. For, alone and filled with a natural need for love, Hester has reached out to another lonely person and found solace and meaning. Nevertheless, as a married woman--although her husband is missing--she has sinned, as has her lover. Still, her sin is solely on her soul; and, because her sin is exposed, Hester's mind is freed and she can seek forgiveness and move forward with her life. Nor does she feel that she and her lover have acted so grievously because Hester declares that their love has a "consecration of its own."
It is the secret sins of both the Reverend Arthur Dimmesdale and Roger Chillingworth that are transgressions of much greater impact. For, they are violations, not just of God's laws, but are also hidden betrayals of other human hearts. When, for instance, Roger Chillingworth, who has admittedly disguised his true identity in order to "prove the ruin" of the minister's soul, ingratiates himself enough to become the private adviser and physician of the Rev. Dimmesdale, he violates the sanctity of the human heart as he deceptively uncovers its secret. "But what distinguished the physician's ecstasy from Satan's was the trait of wonder in it!"(Ch.10) Clearly, Chillingworth oversteps any human role in his pretense of being a physician and "transforms himself into a devil." (Ch.14)
Arthur Dimmesdale's betrayal is that of his congregation, who believe him a holy man. Consequently, he suffers because of the misery of being false to both God and man; however, when he tries to confess at the pulpit, telling his hearers
that he was altogether vile, a viler companion of the vilest, the worst of sinners, an abomination, a thing of unimaginable iniquity....They heard it all, and did but reverence him the more..."The godly youth!" said they among themselves. "The saint on earth!"...Therefore, above all things else, he loathed his miserable self. (Ch.11)
Thus, the people make it impossible for Dimmesdale to confess and he is filled with self-loathing.
Certainly, all three major characters dwell in "the dungeons of their own hearts": Hester bears her own sin as well as the secret that Chillingworth is her husband; the Reverend Dimmesdale bears his secret sin as well as his shame of not speaking up for Hester as she has stood on the scaffold; Roger Chillingworth bears the secret sin of deception and of the evil desire to avenge himself against the lover of his wife. While Hester has been freed by her public exposure and Dimmesdale by his final confession on the scaffold on the New England holiday, Roger Chillingworth essays to the end to control the minister and take ownership of his soul:
"Madman, hold!...Wave back that woman! Cast off this child! All shall be well! Do not blacken your fame, and perish in dishonour! I can yet save you!...."
"Ha, tempter! Methinks thou art too late!" answered the minister..."Thy power is not what it was! With God's help, I shall escape thee now!"(Ch.23)
*Roger Chillingworth holds to his deception to the very end and is, thus, the character who most embodies sin. Not only has he corrupted his own soul, but he has entangled Hester in his deception through threats, and he has violated the sanctity of the heart of Rev. Dimmesdale.