Intention is necessary to achieve excellence, as it initiates the action.  But it is the action, the consistency and the discipline to execute the acts that backs up the intention that are absolutely necessary to achieve excellence.  Intention may be the idea and the notion of what is desired, but the actions to achieve that desire is what speaks to one's commitment and dedication.  Actions speak louder than intentions when it comes to accomplishment.  And while good intentions are noble, positive and needed, these intentions must be backed up by actions to make them a reality.  For intentions rarely manifest anything, only our actions do.

Do you want to know who you are? Don’t ask. Act! Action will delineate and define you.  Thomas Jefferson

You'll never plough a field by turning it over in your mind.  Irish Proverb

What you do speaks so loudly that I cannot hear what you say.  Ralph Waldo Emerson