You'd think it was enough to be the nation's greatest warrior and Thane of Cawdor. What more could a man want? Apparently, a lot. Once Macbeth has had a taste of power, he's willing to kill anyone (men, women, and children) who he thinks might undermine his seat on Scotland's throne. But Macbeth doesn’t get to enjoy being a gansgta for long. He puts his own desires before the good of his country, and, in the end, is destroyed by that ambition. So, maybe you should lay off that nefarious plot you're cooking up to become class president: according to Macbeth, the power and glory just isn't worth it.
In Macbeth, ambition can be good if it's used for the best interests of the country.
Macbeth portrays excessive ambition as unnatural and dangerous, with the ability to ruin individuals and entire countries.