What does Elizabeth mean in The Crucible when she says that John has his goodness now, and God forbid she should take it from him?

John Proctor is a character who was riddled with guilt over his affair with Abagail Williams, and his relationship with his wife became strained as a result.   Proctor is defensive and bristles at even the suggestion (or perceived suggestion) of his past transgression.  Elizabeth says to Proctor "I do not judge you.  The magistrate that sits in your heart judges you."  His sin of adultery has caused major conflicts within Proctor's heart, and he seems to be a man who walks around with a dark cloud over his head.  He wonders if he is a good man, and struggles with the fact that he feels a sinner in the eyes of his wife, but is perceived to be a just and moral man in the eyes of the community.  It is this secret and its accompanying guilt that he and is wife harbor that, like a cancer, causes his soul to waste away.  It is not until the very end, when he tears up his confession, that he finally feels good and just because he knows he is doing the right thing in going to the noose with his good name intact.  In a final act of pure love, Elizabeth declines to save the life of her husband because he finally has achieved the peace and self-assurance that he had been searching for, and "God forbid she should take it from him."