The witches represent a challenge to the natural order: they're women who have seized power by turning against God. Their actions are supported by Lady Macbeth, who, as a powerful woman, also challenges the natural order. The four of them - the witches and Lady Macbeth - encourage Macbeth, a loyal soldier, to go against his masculine nature and kill the King. This, in turn, topples the natural order. As a result, chaos ensues... The moral? Don't listen to women, stay in your God given role, and don't kill the king!