"Stay, you imperfect speakers, tell me more (Act one Scene 3 line 72)" The audience can see that Macbeth, who on the surface is a loyal warrior, will choose to take on evil, in order to achieve his over-vaulting ambition, like what Lady Macbeth says to Macbeth,"Look like the innocent flower, but be the serpent under it (Act one Scene 5 line 72)" The theme of deceptive appearences is once again introduced, and Macbeth is unveiled to us as the evil villain.
The witches also show that Macbeth is easily fooled. They play with Macbeth and trick him with true "lies". After listening to the prophecies, the seed of evil is planted in his heart, and he could not stop thinking about them. He is supersititious, and believed that the witches really have the ability to see into the future. "This supernatural soliciting cannot be ill (Act one scene 3 line 142)" He does not doubt if the prophecies were true, but goes on to plan how he is going to get the throne or how to get rid of Macduff. The apparitions at Macbeth's second meeting with the witches makes him feel over-confident, because he thinks that no one can harm him. This causes him to lose the battle, and die. He is so lost in the prophecies given by the witches that he believed every single word from the witches, until at last he found out that he was being tricked, when unfortunately it's too late to do anything to undo the wrongs he had done to all those innocent people.
While the witches appeal to Macbeth's dark side, Banquo is set as a contrast to the dark Macbeth. Though they both have many similiarities, such as being great warriors and both having promising prophecies, the way they react differently in the more or less same situation provides for us an insight to the huge differences in their characters. For example, even though Banquo is also present when the witches give the prophecies to Macbeth, and Banquo himself about his sons as kings, he does not yield to temptation, and stays true to the King.