In the opening of William Shakespeare's "Macbeth," we have what appears to be a patriotic Scot, talented warrior, and loyal follower of Duncan in Macbeth, and yet, by the end of the play, Macbeth has been a traitor to Duncan, regicide, multiple murderer, and tyrant. One question to ask is what is responsible for this transformation.
The weird sisters are evil characters, and they are portrayed as first putting evil ideas into Macbeth's mind. On the other hand, as they obviously were evil, Macbeth had the option of doing what Banquo did, and turning his back upon them rather than, as it were, consorting with the devil.
When Macbeth begins to fall into evil and contemplate murder, Lady Macbeth strengthens his resolve. She is also a morally suspect character, but since men had more power than women in this period, Macbeth was not forced to listen to her.
Eventually, we must conclude that Macbeth himself must bear full responsibility for his actions.