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There is a commonly used structural/plotting device in drama whereby the nature of the leading characters are elucidated by their varying responses to the same event/temptation/threat. I'm not sufficient a scholar to know if this approach pre-dates Shakespeare but he certainly used it and it has certainly been employed many times since - because it can be very effective.
It's used in Julius Caesar - compare and contrast the conspirators' motivations for assassinating Caesar and it will tell you much about the varied natures of those conspirators.
Here in MacBeth it is used even more prominently - so much so that it is the responses to one act of ambiguous temptation in the first Act that forms the entire action and purpose of the play. Three people are tempted by the prophecies of the Weird Sisters. "Weird" derives a now rare meaning, "fate" from Old English "wyrd", that I am confident Shakespeare was aware of. Think about it; the Fate or Fateful Sisters. Makes perfect and terrifying sense in the context of the play.
So the three people tempted are MacBeth and Banquo, of course, since they were present for the prophecy, and Lady MacBeth, who hears it later from her husband, and stands to gain much, indirectly, if those uncanny sisters speak truth.
I feel that if the basic idea occurred to a contemporary Hollywood scriptwriter today, we'd have the story of virtuous, heroic Banquo, who would die himself whilst killing the usurper, leaving the throne to his son. Shakespeare, however, knew that a flawless hero is actually a fairly boring protagonist and instead relegated him to the secondary but crucial role of person who ignores the temptation but nevertheless reaps the reward offered in the prophecy (if founding a line of kings is any consolation for being murdered on the way to a feast hosted by your former best friend).
More interesting is the morally conflicted man who knows that the quickest way to the throne is also the worst and his ambitious wife who urges him on though she, when it comes to it, cannot do the evil deed herself.
So first we have the contrast between the good man and the bad, then we have the contrast between the initially reluctant man who goes on to commit crime after ever more brutal and heinous crime and the woman that, though she did nothing directly herself, becomes ever more remorseful and unhinged, until she can stand it no longer, her prayer to be "unsexed" having not been answered.
These contrasts reveal the Tragedy of the potentially great and good MacBeth.