Macbeth: Influencial People In life there are many people who influence our lives, some influence us to try to get us to do bad things and others who influence us to do good things. Throughout the course of Shakespeare’s play, Macbeth, there are several people who influence him to murder King Duncan and help lead him to his downfall. The first people to influence him are the three witches. I think the witches play a big role in influencing Macbeth to kill Duncan. I think this because when they meet him and Banquo in Scene ii of Act I they tell him that he is,” the thane of Glamis, that he will be the thane of Cawd