What you have accomplished in the past is a much stronger example than talking about what you are capable of doing in the future. Actions do speak louder than words!
from How Valuable Are You
Setting an example is not the main means of influencing another, it is the only means.
The legacy of heroes is the memory of a great name and the inheritance of a great example.
Nothing is so contagious as example; and we never do any great good or evil which does not produce its like.
Francois de la Rochefoucauld