"It is well to preach, as I do, with my lips. But you can all preach with your feet and by your lives - and that is the most effective preaching! The preaching of holy lives is living preaching! The most effective preaching from a pulpit is that which is supported by godliness from the pew! God help you to do this" (source)
Recommended reading:
You can also listen to an audio recording of The Forgotten Spurgeon on Sermonaudio.com: