Elizabeth Proctor is tested in many ways by the events that take place in the play. Before the play even begins, her husband sleeps with their servant, Abigail Williams, and she must confront him about his infidelity. He admits to the affair, so she fires Abigail. Then, in act 2, she learns that John was alone with Abigail in the town, a fact that tests their relationship and her trust again. Now, he is afraid to tell people about what she told him: that the dancing in the woods was only "sport." She asks him, "John, if it were not Abigail that you must go to hurt, would you falter now? I think not." Her marriage is clearly tested by her husband's infidelity and her own lack of trust and confidence in his love.
Then, Elizabeth is arrested. She is accused by Abigail of sending out her specter to torture the girl at dinner. However, Elizabeth predicted this would happen, telling John that Abigail "thinks to kill [her], then to take [her] place." The metaphorical heat is turned up even higher when Elizabeth lies to the court, saying that the only reason she dismissed Abigail from her employ is because she was dissatisfied with Abigail's work. This comes after John had already told the court that Elizabeth fired Abigail because of his affair with the girl. Elizabeth's honesty is tested, and she fails because she is trying to protect her husband; it is an extremely unfair test. She puts her husband's reputation in the town ahead of her own soul. It is a kind and loving thing to do, but it essentially seals both of their fates.
In act 4, Elizabeth admits that she "[has] sins of [her] own to count. It needs a cold wife to prompt lechery." Moreover, she asks for John's forgiveness by saying, "Forgive me, forgive me, John—I never knew such goodness in the world!" She removes some blame from him, taking some responsibility for the challenges they faced in their marriage. This makes it easier, I think, for John to forgive himself for his sin of infidelity. In the end, she is tested again. She could try to persuade him to confess and lie in order to live, but she knows that would compromise his integrity. She does not want him to think worse of himself: when he decides to lie to save his life, she does not judge him. When he changes his mind—a judgment that will result in his death—she thinks only of his integrity and goodness, placing it above herself or her own wishes. Of course she wants him alive, as she tells him, but she will not put her wishes ahead of his. In fact, she has the last words in the play. She says, "He have his goodness now. God forbid I take it from him!"