Another way to be a highly persuasive speaker is to be “real.” Your audience will find you more trustworthy, and so they will be more willing to hear–and agree with–your point of view.
To do this, understand what you are saying, and believe in it. If you don’t believe in a part of your talk, find another way to say it or present it so that you do believe in it. In other words:
Find a sense of truth. Most people think that acting is about pretending, being someone else, and being a good faker. Actually, it’s all about finding and demonstrating a sense of truth in what you’re saying.
Actors are not judged by what they say, or even how they say it, but on how they make the audience feel, and how effectively they create belief in the reality of the story they’re enacting. They’re judged on how convincing they are. Each and every successful actor does this her own way, by playing the part using parts of herself.
Speakers are also judged on how convincing they are. As a speaker, your job is to know what you want to say–know your lines, if I can extend the theater metaphor–say them well, and be convincing. Your job is to get the audience to believe in you and your message: you want them to suspend their disbelief, to drop their skepticism, move out of their inertia, and comply with your request.
The best way to do this is to draw on your own experience as you bring the material to life. Doing so will lend your speech a deeper sense of truth.