Great talkers, little doers.
The worst wheel of the cart makes the most noise.
Wise men don't need advice. Fools won't take it.
Whoever shall introduce into public affairs the principles of primitive Christianity will change the face of the world.
When the well is dry, we know the worth of water.
...it is prodigious the quantity of good that may be done by one man if he will make a business of it.