Why does Chillingworth want to exact revenge on Mr. Dimmesdale in The Scarlet Letter by Nathaniel Hawthorne?

In his conversation
within her jail cell,says, several times, of Hester's co-sinner, who turns out to be the
Reverend, "He shall be mine!" or "Thou wilt not reveal his name? Not the less he
is mine." He says that he will not "interfere with Heaven's own method of retribution,
or . . . betray him to the gripe of human law."  Therefore, Chillingworth vows that he will
not turn the father of Hester's baby over to the town authorities but that, instead, this man
will "be his." What can this mean? Hester is clearly concerned and interprets these
words as very threatening. She says, "Thy acts are like mercy . . . but thy words interpret
thee as a terror!" She means that what he says he will do sounds mercifulthat he will not
turn the man over to the lawbut the words themselves are frightening. Chillingworth does want
revenge because, as he says to Hester, this man "has wronged us both!" He feels that
he shares some responsibility for Hester's...