The key figure that this statement can be seen at true through is John Proctor. Through the conflict of the trials-specifically, his wife being charged, and then he himself being charged-he grows and changes quite a bit. At the beginning of the play, he is introduced by Miller as "regard[ing] himself as a kind of fraud" and as "a sinner" with a "...troubled soul". His affair with Abby has shaken his confidence in himself; he feels guilty, like a bad person, and feels like he has to make up for that to his wife, to himself, and to God. He goes about his days, confident and assured, but underneath it he feels himself inferior and lacking.
We see some of his struggle as he argues with Elizabeth in act two; he wants to see some kindness from her, and she is still holding resentment. So their relationship is strained, and John is resentful of that fact. But, when Elizabeth is taken, he puts that all behind him, and promises Elizabeth that he "will...fall like an ocean on that court." He is a man in action, bound and determined to save his wife, who minutes before, he had been arguing with. This is his first step towards growth, and towards an acceptance of himself.
Later, in act three, he is prompted to confess his adultery to the entire court. Here, he puts aside any pretense, and any hypocrisy, and confesses, openly, "I have known her, sir...I set myself entirely in your hands," turning himself over for whatever punishment might come. This shows his willingness to let go of his last shred of reputation; he has grown into that. After he is accused and jailed, he has a long time to sit in jail and think about things. His self-confidence is shot though, and as he speaks with Elizabeth for the last time, he confesses to her that "my honesty's broke, Elizabeth; I am no good man." He feels that if he gets up there and is hanged, it is a sinner that does it, a hypocrite. He is not a "saint" to walk up there and stand for honesty and integrity before the entire town.
However, by the end, we can see that his conflicts have indeed helped him to grow; he tears up the confession, and decides to hang. He feels, finally, after speaking with Elizabeth, after trying to save her and her friends, after being falsely jailed, that he has paid his penance. He makes the right decision to not confess, and states of it, "I see some shred of goodness in John Proctor" and can walk to the gallows with a clean conscience. Conflict has helped John to grow from a conflicted, resentful man, to one who feels at peace with his soul and his life. I hope that those thoughts help; good luck!