The usual phrase is, of course, “talk the talk and walk the walk”, meaning to both say and do the right thing. If anyone can definitively point to the origin of this phrase, I’d be interested to know it — possibly from the US civil rights movement of the 1960s.
It’s been mentioned more than once that the Stanley Kubrick movie Full Metal Jacket, the character Joker bandies words with a marine called Animal Mother, who answers: “You talk the talk but do you walk the walk?” This encounter may be significant purely because Animal Mother’s helmet bears the text “I AM BECOME DEATH”.