Because Proctor was a Puritan, his daily life was surrounded by Christian rules, specifically the 10 Commandments and the 7 Deadly Sins. Here is how the Puritans thought about the soul: Imagine a white piece of paper. Every sin or wrong doing ever done was a mark on that paper. These marks could never be removed, and each mark would incur the punishment of Hell. Sadly, the Puritans had no way of cleansing their sins and starting fresh, and every sin, down to the smallest lie, would lay heavy on their minds.
John Proctor, in the play, is a strapping man in his 30s, with a timid wife, Elizabeth. Proctor cheats on his wife with Abigail-- breaking the Commandment on adultry and the deadly sin of lust. However, Proctor is a deeply moral man, even if he is flawed. On the outside, he knows that people respect him for his truthful word and courage to do and say what he believes to be right, but inside he only sees his fault of adultry. He calls himself a fraud throughout the play, thus creating one internal conflict.
His second internal conflict his when he is given the choice to lie and say he is a witch and save his life or die being truthful. His icon of goodness, Rebecca Nurse, stands firm to the truth-- that she is not a witch, and if she must hang for telling this truth, then so be it. Here again, Proctor is conflicted. In the moments before his death, he asks his wife, Elizabeth if she would lie to save herself, and she can't answer. Because he considers himself a fraud anyway, he knows he feel ridiculous standing on the gibbet next to Rebecca Nurse, looking like a martyr when he knows he is not. He grapples with the decision before asking for his life; he knows it is wrong, but there is a part of him that gives up the battle to be a "good" Puritan since he feels he is lost to Hell anyway.
In comes the external conflict with Judge Danforth. Danforth, being a stoic, broken judge, feels elated when Procotr says he is witch. However, Danforth pushes Proctor too far when he asks him to sign a document saying he a witch and the document will be posted on the church door. Proctor, continuing to grapple with his emotions over lying the first place, becomes aggressive when asked to name the others he "saw with the devil". When he refuses, Danforth realizes that Proctor is openly lying and he pushes him to sign the document after Reverend Hale begs for Proctor's release. With a shaking hand, Proctor signs the document, but he refuses to give to Danforth, saying that everyone saw him sign it so why do they need it? Danforth threatens him, and finally, when pressed about why he won't give them the document, Proctor's emotions finally break through. His name, his good name-- and the respect that surrounds it- is the only thing that Proctor feels is good about him. He screams that his name is the only name he will ever have- how can he sign himself to lies when the other people in the village died for the right cause?
Proctor goes to his death with the comfort of saving his good name and the name of his sons in the village. They would continue to have the respect of the people around them, and Proctor feels that he has redeemed himself for his poor past decisions. Even Elizabeth, when cajoled by Rev. Hale to make him change his mind, refuses to talk to him out of his decision saying in the last line of ACT IV, "He has his goodness now. God forbid I take it from him."