Watch your thoughts; they become words.
Watch your words; they become actions.
Watch your actions; they become habits.
Watch your habits; they become character.
Watch your character; it becomes your destiny.
— Frank Outlaw
“Frank Outlaw” doesn’t seem to exist. The quotation is attributed here to “Elizabeth C.”
Here is another, more poetic variation found at Quoteland.com:
“Be careful of your thoughts, for your thoughts inspire your words. Be careful of your words, for your words precede your actions. Be careful of your actions, for your actions become your habits. Be careful of your habits, for your habits build your character. Be careful of your character, for your character decides your destiny.”
~ Chinese proverb
The Josephson Institute of Ethics sites another varation:
Thoughts lead on to purposes; purposes go forth in action; actions form habits; habits decide character; and character fixes our destiny.
(Josephson Institute Editor’s note: This quote is commonly attributed to Tryon Edwards, a 19th-century American theologian and editor. Note the similarity of this quote to the one above.)
Addition: The Bible adds:
“Be careful how you think. Your life is shaped by your thoughts”
Frank Outlaw has another quotation attributed to him but it’s really, really bad, so jump over with fair warning. Get a third quote and Frank rises to mythic stature. Still, the destiny quote is compellingly simple.
My money for the original is on the Chinese, or at least it was until I came across the minimal form in Proverbs.