It is said that the flavor sensed by our tongues actually makes up less than 20 percent of the taste of delicious food. The other 80 percent comes from a dish's aroma, its temperature and other factors that we sense overall. With lectures and the like as well, research shows that listeners apprehend only about 7 percent of a talk's content, and more than anything, what notably remains with listeners are things like the speaker's personality and attitude, impressions of their manner of speaking and so forth.
When listeners feel confident that the person speaking to them is trustworthy, they lean in towards the speaker and nod in agreement while listening. But when for some reason or another they get a sense that the speaker can't be trusted, no matter how good the message of the talk, listeners' hearts will not accept it.
Whenever I share the Buddha's teachings, I watch listeners' faces so to see whether my words are reaching their hearts, but although I remain attentive to the expressions on people's faces as I talk, I think honestly is the clincher.
When you speak the truth in your own words with no pretensions, you will definitely persuade everyone listening to you, and it will show on their faces. But if you try to be emphatic about something you've never attempted or accomplished yourself--simply as a line for public consumption--your worlds will never be genuine. That's because you speak without confidence. Listeners have keen ears for this difference.
From Kaisozuikan 9 (Kosei Publishing Co.), pp. 102-103