We should not assume that our listeners will know what the relevance of the speech is. A good speaker clearly establishes why the topic affects the audience. Even through disagree- ments, an effective speaker shows that there are more similarities than differences. But an effective speaker does not forget those differences. In your audience, people will digest what you have said in several different ways.
Listeners interpret messages according to life experiences, values and opinions.
I once asked a class what they thought of one particular candidate who was smiling and laughing while answering questions. One student was very impressed, saying that these gestures made him look friendly and casual. The student in the next seat grunted loudly at this response, and couldn't understand this opinion at all, saying without hesitation, that the candidate was clearly smirking and being arrogant. They wanted to know who was right. They both were.