Macbeth's role

I think Macbeth is a great story, because Shakespeare not only showed us a interesting and intense story, but also went into character's mind, especially Macbeth. As the protagnist of the story, Shakespeare wrote more about him than anyone else. Most people think Macbeth is the source of evilness, but I think he is just a tool of evil. The person who are really evil are the witches. Remember, at the beginning of the story, Macbeth is just like Banquo, they both loyal to the king and they were good friends, but the witches' predictions break up this peaceful world. They lure Macbeth deeper and deeper to do the wrong things like killing Duncan then Banquo, he is not evil inside, it is just that, he is really confused, we can see that when he was about to kill Duncan, he does not want to do it, but the witches' predictions tell him that he can do it. He was just being used, that is why I'm saying Macbeth is the tool of evil but not evil itself.