Answer: When they gain power, some characters use it for wrong purposes. For them, power brings nothing good, and they are better off without it.
Explanation:
It is well known that one of the main themes in Macbeth is power and ambition to gain it - this is primarily demonstrated in the character of Macbeth himself, but also in other characters.
At the beginning of the play, it seems that Macbeth does not have much power - in fact, it is his wife that has power over his life. Lady Macbeth is the one that persuades him that he must become a king at all cost, and puts him under pressure to kill King Duncan. Lady Macbeth is, at least at the play's beginning, presented as one of Shakespeare's strongest female heroines. Macbeth blindly follows her instructions, even though he might find them wrong.
Moreover, the Three witches also have power over Macbeth's life - through their prophecies, they directly influence Macbeth's actions. Even when Macbeth does gain power and become a king, he is consumed by guilt which leads to his downfall. Macbeth's power, therefore, becomes his weakness. He feels guilty, hallucinates, and eventually loses his power and dies. This is what happens with Lady Macbeth - she takes her own life when she sees the extent of her and Macbeth's wrongdoings.
Other characters in the play, such as Macduff or Malcolm, use power for different reasons - they have noble intentions and are modest in their attempt to gain power. Macduff uses his power only when he has no other choice. When his wife and children are murdered, his power is his main tool to revenge them. It is easy to see how these characters use power for different purposes.
