I think that the ability to speak well and clearly about a topic is one of the most difficult skills to master.
Overall, I think that there are ways to be "correct" in your speech and still present a very strong point of view. Look at the Dalhi Lama. He is very clear in his message, despite having many people attacking him. I think that this is why he has had such staying power and has had an impact on the world,
This topic also brings to mind a wonderfull moment in the origanal Star Trek TV show,,,
Lazarus "how can you not believe me , you are being a fool"
Spock "I have simply examined all of the relevant information and come to the logical conclusion that you are, in fact, a Liar"
Star Trek the Origanal series "The Alternative Factor"