John and Elizabeth are characters from a crucible which is a play. In the act, Elizabeth says that she won’t take john’s goodness because john made up for his past sins. Now he has finally decided to sacrifice his life for what is right.
In this whole case Elizabeth doesn’t want to draw john back or stop him from doing anything that is actually right. Plus, now he finally knows that he has self-respect and has some goodness in him. It is wrong to change the mind of a man on his path to riotousness and Elizabeth just doesn’t want to do that.