In the play Macbeth the characters are using certain prophesies to try and helpthemselves in gaining confidence and self-assurance in achieving their ultimategoals.
This is especially true in the character of Macbeth. He believes thatthroughout this story he is able to control his destiny and also change thingshe can not. He thinks that the actions he takes and the decisions that he makeswill allow him to control the future and further himself. In the beginning ofthis play, Macbeth is encountered by three witches, which give him the news ofhim becoming the king. He does not allow this to get to him initially but whentheir prophesy of him becoming the Thane of Cawdor comes true, he takes theirother words a lot more seriously. He then puts into action the killing of KingDuncan. By this move, he is able to take the throne. This finalizes the witchesinitial prediction of Macbeth becoming the king.
His rule of Scotland is verytumultuous and questions arise of his ability of being able to rule properly andhis previous actions. He then murders his friend Banquo and then again consultsthe witches. They provide him with three more prophesies. One to beware ofMacduff, one that he cannot be killed by any man born of woman, and the finalsaying he cant be killed until Birnam Wood moves. Delighted by this news,Macbeth is filled with more false hopes and confidence. But inevitably hisbelief and trust in his ability to know the future and be filled with suchconfidence catches up to him. He is overwhelmed by all the true prophesies givenby the witches and his eventual overthrow by Macduff. The story of Macbeth isbasically a story of one mans attempts to control the future.
Macbeth usesall his abilities and all his resources to try and accomplish this, but in theend it fails him. He bases all of his actions on his knowledge of the future andhis attempts to change it. The whole story is based around the idea of hisknowledge of what is to happen, and his attempts to change that towards his ownbenefit.
It provides him with the false hopes that were an eventual contributorto his downfall.