There is certain level of confidence required to accomplish anything in life. While confidence can be one of your greatest strengths, it becomes your worst enemy if you cross the line and become cocky or arrogant. The same goes for ambition. It can be one of your greatest strengths as long as you maintain humility.
“Perhaps the only way to be both humble and ambitious is to be ambitious for the good of others.” John Hennessy
The best way to balance ambition and humility is to make sure that your ambitions are focused on things greater than yourself.