Macbeth is overly ambitious. He shows his great concern right after hearing the three prophecies foretold by the three witches, including the one saying that he will be the future king of Scotland. He is so eager to know more about those predictions that he asks those witches to stay, accusing them as the “imperfect speakers” and urges them to tell him more. He remembers every word those witches tell him that he even speaks to Banquo “Your children shall be kings”, showing he worries that Banquo will threaten the crown which he thinks he deserves. After the prophecy of being the Thane of Cawdor fulfills, he can no longer stop the evil seeds growing in his mind and these are what he speaks to himself: “Stars, hide your fires!/Let not light see my black and deep desires; The eye wink at the hand, yet let that be,/Which the eye fears, when it is done, to see”, all implying that he is ready to do something for the greatest behind.
With the evil seedling growing bit by bit, Lady Macbeth plays an important role in helping Macbeth’s ambition to grow even more, until he believes that he is invincible. She knows that Macbeth has thought of being the king, she knows that sometimes he is just “too full o’ the milk of human kindness/To catch the nearest way”, therefore she pushes him further, almost forcing him to murder Duncan by using her cunning words. She says that if Macbeth commits the murder, he will “Be so much more the man”; if not, he is just a coward. She encourages Macbeth to arrange the murder plan, asking him to screw his courage. Even when Macbeth’s ambition starts to decline after the murder owing to his guilty and regretful feelings, Lady Macbeth keeps on strengthening him. She asks Macbeth “Consider it not so deeply”. Saying that a little water can clear them of the deed, she promotes the idea that sins can be washed away easily. This also builds up Macbeth’s confidence to himself.
Now that Macbeth successfully becomes the king of Scotland, he really thinks that he is powerful enough that no one can touch him anymore. In order to secure his crown, he can commit evil deeds, even to his friend. He sends two murderers to murder Banquo and his son Fleance, because he is afraid that they will threaten his position as the king, like what the witches have predicted before. However, he doesn’t tell Lady Macbeth what he is going to do. He asks her to “Be innocent of the knowledge”, this shows he is confident that he believes he can tackle those problems by himself and so there is no need to share his plans with his wife anymore. To make sure anyone in his way is put down, he kills Macduff’s families as he is warned by the apparitions to beware of Macduff.
By the end of the play, Macbeth is too confident that he disregards the apparitions’ warnings of Birnam Wood moving to Dunsinane, and that no man born of a woman will harm him. Macbeth actually takes these warnings literally, knowing that no tree can uproot itself, and that everyone is born of a woman, having a mother and father. Finally, no matter who warns him of the danger of the approaching rebellious armies, and how many times he is told that these reports are true, Macbeth is ignorant and ignores them because he still believes that he is invincible. This disregard and ignorance towards these prophecies is what eventually leads to his death. If you sing before breakfast, you will cry before night. When he notices that he is only a toy of the witches, it is already too late. Yes, his way of life has fallen into the sere, the yellow leaf… though he chooses to stand on the ground for the last battle in his life.
Human beings have both good and bad natures. Macbeth’s over ambition drives him crazy, making him abandons his good side, turns to the evil side to commit series of murders without thinking about the consequences. With the interposition of Lady Macbeth and the three witches, he builds up his invincible confidence, which leads to his lack of judgment, trusting all the witches tell him, when all along they are just playing him to their own will. He falls, in spite of how bright he is at the beginning of the play.