The witches then foretold, “Macbeth shall never vanquished be until Great Birnam Wood to high Dunsinane Hill Shall come against him” (IV.i.92-94). Lo and behold later the army decided to hide behind the trees as camouflage from Birnam Woods. Everything that the came true no matter what the circumstance. The witches have made everything come true in the witches foretold the prophecies. Are these prophecies or are they just facts spewing from the witches? Either way they are right and there is no question about it.
Some people will argue that greed had the most influence. Greed had encouraged many people to do what they did instead