Theme of good vs evil
"Fair is foul, and foul is fair" (Act 1, Scene 1) - This quote from the witches introduces the theme of good versus evil, blurring the lines between both.
"There's no art to find the mind's construction in the face" (Act 1, Scene 4) - Duncan expresses that one cannot judge a person's true nature by their appearance, highlighting the theme of deception associated with evil.
"Out, out brief candle! Life's but a walking shadow, a poor player that struts and frets his hour upon the stage" (Act 5, Scene 5) - Macbeth reflects on the futility of life, culminating in a sense of despair and the pervasive presence of evil.