At the beginning of the play Macbeth is the "bravest" soldier and the honorable Thane of Glamis. His rank and nobility are of great value, and he seems to be fit for his status. But his encounter with the witches awakens in him a deep impatient ambition. Immediately after the first prophecy of being Thane of Cawdor becomes true the "horrid image" of the murder of King Duncan in order to become king himself crosses his mind. He is not totally cold and solely ambitious as shown by his terror of the murder image, which thoroughly defies his loyalty. There is love in Macbeth as shown by his letter to Lady Macbeth in which he calls her his "dearest partner of greatness." Macbeth is already thinking about being king but he is undecided about whether it is better to succumb to the temptation presented by the witches or to wait for Fate to crown him. Banquo warns him that at times evil forces "tell us truths . . . to betray's in deepest consequence."
Even though he does not state it out loud, Macbeth does care about morality and religion, as demonstrated in his soliloquy (I, IV, 12-28) where he lists the three reasons why he should not kill Duncan: he is "his kinsman," "his subject" and "his host." Macbeth adds that "Duncan hath born his faculties so meek, hath been so clear in his great office, that his virtues will plead like angels." Lady Macbeth knows her husband and feels that he is "too full o' th' milk of human kindness." To counter this she accuses Macbeth of being a coward if he does not kill Duncan. Macbeth does not want to be a coward, either as soldier or as husband, so he accepts to murder Duncan. His ambition and self-image of bravery win over his virtues. Nevertheless he is remorseful after murdering Duncan, and he masks his fear of being found with rage against the supposed murderers and thus kills the drunk guards.
Already being king Macbeth is troubled by remorse and cannot sleep easily. Also, Macbeth is fearful of Banquo because he knows what the witches prophesied and may suspect Macbeth. Another thing that bothers him is that he has the demeanor of a king and that the witches promised Banquo a lineage of kings while they only promised him to be king. He refuses to accept that he turned evil just for Banquo's lineage to be kings and so decides to challenge Fate by killing Banquo and his descendants. Once he does he is haunted by Banquo's death and troubled because his son Fleance escaped. He is also worried about the loyalty of other lords, like Macduff. Overall, Macbeth exchanged his peace of mind and virtues for a troublesome crown by allowing his impatient passion for desire of power to overcome his senses. This clearly illustrates that "foul is fair and fair is foul."
As time advances Macbeth is more and more unsure about his security as king. To know the best or worst the future holds for him, Macbeth visits the witches. The witches reassure him that he will reign. Through apparitions he is told that he will not be defeated until the Wood of Birnam comes to Dunsinane and that anybody born of woman cannot harm him. Both of these seem impossible events to Macbeth. The images of a line of kings in Banquo's likeness does torment him, though. The magnitude of his relentless and now evil morality shows through his orders to assassinate all of Macduff's family when he finds out that Macduff has fled to England.
The news that Malcolm and his troop come to Dunsinane annoy him, but he rests on the promises of the witches and refuses to be afraid. By this time Macbeth is wary of all the trouble being king has brought him. He laments that even if he prevails he will not have honor, love , and obedience in old age. He fully laments that being king is not worth the peace of mind he and Lady Macbeth enjoyed before. Also the health of Lady Macbeth worries him. Her suicide does not strike him so much with grief but rather unleashes his disenchantment and pessimistic view of life. He bitterly reflects: "[Life] is tale told by an idiot, full of sound and fury, signifying nothing." And when he discovers that Birnam Wood apparently moves toward Dunsinane he realizes that the witches cheated him. Nevertheless, he decides to die honorably in battle. On seeing that he will lose the war, he considers but then dismisses suicide. He still clings to the second prophecy of the witches that nobody born of woman can hurt him.
When Macduff encounters Macbeth the small but still present moral consciousness of Macbeth is shown through his refusal to fight Macduff because his is already too guilty with the blood of Macduff's family. Macbeth is sure he will kill Macduff too because he is born of a woman. But when Macduff declares that he was "untimely ripped" from his mother's womb Macbeth is afraid and still refuses to fight. Only when Macduff threatens to tie him to a pole and make of him a public spectacle does Macbeth fight Macduff. Macbeth still has dignity at the end and proves not to be a coward by perishing in battle.
Macbeth was tempted and cheated by the witches. His own ambitions and passions deceived him into changing his virtues for unrest and immorality. At the end he is wary of life and fully aware of his deception. He pays all the consequences of his betrayal but still dies like a brave soldier.

Lady Macbeth fulfills her role among the nobility and is well respected like Macbeth. King Duncan calls her "our honored hostess." She is loving to her husband but at the same time very ambitious, as shown by her immediate determination for Macbeth to be king. This outcome will benefit her and her husband equally. She immediately concludes that "the fastest way" for Macbeth to become king is by murdering King Duncan.
Lady Macbeth's immediate thoughts may make her appear as thoroughly irreligiously cold and ambitious, but this is not so. To prepare for what she feels must be done she calls on evil spirits to "stop up th' access and passage to remorse" in order to be relentless. Otherwise her conscience would not allow her to act.
Furthermore, Lady Macbeth knows her husband well. She thinks he may be too kind in order to murder King Duncan. This is why she represses her conscience so she can later usher Macbeth into commiting the deed. At first Macbeth agrees. But later Macbeth wavers in his decision. But Lady Macbeth is sure that being king is what Macbeth really wants and that this is the best for both of them. So, in response to Macbeth's uncertainty, Lady Macbeth manipulates him by questioning his manhood and his love for her. She is successful because regardless of his own conscience Macbeth carries out their plan of murder.
The almost superhuman strength Lady Macbeth rallies for the occasion and her artful and sly ability are shown through her meticulous attention to detail regarding the murder. When Macbeth returns to their chamber she goes back to the murder scene and cleverly smears the grooms with Duncan's blood. However, her morals had prevailed just a while before as revealed through her comment that she would have killed Duncan herself had he not "resembled [her] father as he slept."
Perhaps Lady Macbeth felt that suppressing her conscience for the deed was enough and that later the thought of the deed would just dissipate. The outcome is not this way, though, because Macbeth and Lady Macbeth often cannot go to sleep, and if they do, they experience terrifying dreams. But still, Lady Macbeth is able to maintain her sanity and composure during the day, even more than her husband. She urges him to be light hearted and merry. Once she practically rescues Macbeth from the frailty of his own conscience. When Macbeth sees Banquo's ghost she creates an excuse to explain his odd behavior. She attempts to chasten Macbeth by again questioning his manhood. When the situation grows worse though, she takes charge once more and promptly dismisses the lords from the feast.
Later, though, the burden of Lady Macbeth's conscience becomes too great for her and her mental and physical condition deteriorates. A gentlewoman observes her sleepwalking and consults a doctor. The doctor and the lady observe Lady Macbeth sleepwalking, madly trying to cleanse her hands of the blood of Duncan and Macduff's family. Still in her sleep, Lady Macbeth asks, "what, will these hands ne're be clean?" foreseeing that she will never have peace of mind. She also retells events of the day Duncan was murdered. The doctor tells the gentlewoman that what Lady Macbeth needs is spiritual and not physical help.

Lady Macbeth's condition worsens, and she goes in and out of sleep with delirious visions. Macbeth asks the doctor to cure her or give her a drug that will erase the troubles of the heart. The doctor responds that he cures physical not moral problems. Later, as the battle ensues outside of Dunsinane, by unspecified means Lady Macbeth commits suicide.

At the beginning Lady Macbeth finds strength to entice Macbeth to murder Duncan and to follow through with the murder herself. As time advances though, her pretended strength diminishes as she fights the torments of her conscience. Tending to her conscience engulfs and destabilizes her so that she can not support Macbeth against Malcolm. Lady Macbeth's attempts to suppress her conscience fail. At the end she chooses death because she can no longer bear the torments of her guilt.