A boxing match doesn't start in the ring, it starts in a press conference. For some reason, boxers 'bad mouth' their opponent as if the points were counted.

As a boxer, no matter how tough you sounded while holding the mic, if your opponent in the ring gets the chance to punch you really hard in the chin first, most likely you'll be knocked out.

You can keep on telling people you're a champ, but your words won't matter if you get knocked-out first.

Remember when you were a child? You believed every funny and scary story your uncle told you. As if it's a fact. Then you tell the same stories to your friends. Only embarrassed to find out later on that the stories were just fiction. (Kwentong Barbero!)

That's when you decided to pay attention to their action instead of just the words they say.

Why does action speak louder than words?

Unlike words, your actions can't lie. Instead, it confirms what's in your thoughts or intentions. You can retract a statement or change your opinion anytime but you can't undo something that's already done.

Don't get me wrong, 'Words' do speak. But ACTION speaks louder. It tells what you don't need to say.

That's why, "Do as I do" is more effective than 'Do as I say'. 
    People may doubt what you say, but they will believe what you do. ~Lewis Cass