don't talk the talk if you can't walk the walk

Do not make claims that you are not able to back up with equivalent actions. Anybody can run their mouth like that, but don't talk the talk if you can't walk the walk. A: "Bah, that's not impressive. I could do that with one arm tied behind my back!" B: "Go on then, show us. Don't talk the talk if you can't walk the walk!" That consultant has all these radical ideas that he wants to pitch to the boss, and I've warned him—Don't talk the talk if you can't walk the walk.