Macbeth's goal was not to become king until the witches made him believe it was his destiny. In the play, Macbeths destiny was paved out by the witches. Destiny is not something that can be changed. A person has control of his/her destiny. Macbeth's destiny was suggested by the witches, he listened to their suggestions and followed them. In Act I, Scene III, the witches tell Macbeth that he is Thane of Glamis, Thane of Cawdor and that he shalt be king hereafter. Immediately after hearing the witches prophecies that he will be king, Macbeth thinks that he must kill the current king to become king himself. If the witches had not met Macbeth, he would not have become king. His ambition grew more after they told him he would become king of Scotland. The witches seem to have been planning on meeting him because they knew he was going to the impossible in order to become king. If the witches had never met Macbeth, he would remain being Thane of Cawdor. Macbeth would have continued to be loyal and would have not betrayed God, the King, Scotland and himself. Macbeth would not have acted paranoid and see his life as an empty meaningless charade. .
Macbeths character changes throughout the play. At the start he is a war hero "brave Macbeth" who has defeated the enemy. He becomes greedy and wants power. His doubts come into his mind about whether he should kill Duncan and after that he becomes obsessed with the prophesies and wanting to wipe out anyone that doubts him as king. At the beginning of the play Macbeth is introduced as the conquering hero who has just defeated the enemy. Also at the end he is shown as a warrior who has died in battle. This is when Macduff kills him. In a way he is sort of a tragic hero because he was a hero at the start but power hungry his greed got the better of him and this was quite tragic.His meeting with the witches make him consider himself as king. Before his encounter and during it he was surprised by their prophecies and intrigued after that.