Macbeth meet the three witches. Three witches told him that he would be the 'Thane of Cawdor' and the king of Scotland.
You will be the king
Macbeth betrayed king Duncan and became the king of Scotland.
Macbeth didn't trust his friend Banquo and murdered him. The ghost of Banquo appear in a banquet. Macbeth is angry and feared.
Macbeth meet three witches again and ask for the future. The witches told him that he would be safe until the tree move down the hill and no one born from a woman can kill him. Macbeth trust that and though that he is unbeatable.
Malcolm, the son of Duncan, formed up an army in Ireland and England to revenge on Macbeth. The army disguised as tree and move to the castle of Macbeth. Malcolm killed Macbeth because he was born from his mother's womb.