Things are tense between John and Elizabeth Proctor as The Crucible by Arthur Miller begins. We learn pretty quickly that John has had an affair with a former servant girl, Abigail Williams. Seven months ago Elizabeth felt this was happening and fired Abigail; John subsequently confessed everything.
Abigail reveals that all this talk of witchcraft is foolishness and declares she wants to restart the affair. Proctor refuses. He tells her:
Abby, I may think of you softly from time to time. But I will cut off my hand before I’ll ever reach for you again. Wipe it out of mind.
When act two opens eight days later, we see the Proctors together for the first time. Their conversation is stilted, and it is clear that things are still awkward between them.
Proctor, with a grin: I mean to please you, Elizabeth.
Elizabeth - it is hard to say: I know it, John.
He gets up, goes to her, kisses her. She receives it. With a certain disappointment, he returns to the table.
Both of them are trying, but things are not going well. The stage direction reads: A sense of their separation rises.
Elizabeth tells John their new servant, Mary Warren has been going to court for the trials, and she thinks John should go to tell the courts what he knows about the girls lying.
This is actually a good thing, for it means they are actually talking about things that matter rather than just the weather, the crops, or their sons. It is also a problem, however, because now Elizabeth insists that he go tell the court what he knows. Proctor grows increasingly angry and agitated until he finally admits he cannot prove it because he and Abigail were alone.
Of course, Elizabeth is immediately upset that he was alone with Abigail--he had obviously not told her that part of the story. An argument ensues and both of them are upset. Elizabeth is disappointed, but John is angry, mostly out of his own guilt. Finally he shouts at her:
Let you look sometimes for the goodness in me, and judge me not.
Elizabeth: I do not judge you. The magistrate sits in your heart that judges you. I never thought you but a good man, John - with a smile--only somewhat bewildered.
This is the truth of their relationship. It is clear that John still loves his wife (who has forgiven him), but he has not forgiven himself. When Elizabeth is arrested, he knows he must act. He tells the court that Abigail is lying and admits his crime of adultery. Elizabeth tries to save him from punishment and is willing to lie to do it, but Proctor is arrested anyway. Both are willing to sacrifice themselves for the other, but their efforts fail.
In the final act, before Proctor is hanged, John asks Elizabeth's forgiveness. She replies,
John, it come to naught that I should forgive you, if you’ll not forgive yourself. It is not my soul, John, it is yours.
Elizabeth takes the blame for his turning away,
John, I counted myself so plain, so poorly made, no honest love could come to me! Suspicion kissed you when I did; I never knew how I should say my love. It were a cold house I kept.
This is enough to make John want to save his life by signing his name to a lie, but in the end he cannot do it, even to spend the rest of his life with his wife and family. When others try to get Elizabeth to make Proctor sign, she refuses, saying, "He have his goodness now. God forbid I take it from him."