There is also, however, the credibility that comes from saying or writing something that the audience already believes or that reinforces the audience's experience. We should treat this kind of ethos with a healthy dose of suspicion. Just because something sounds right to you or makes you feel good about what you believe does not mean that it is true.
Take, for example, the idea that the Founding Fathers of the United States were Christians. Many well-known commentators and politicians have made this claim, and it has been generally accepted as the truth. The statement has the authority that comes from being the conventional wisdom. The problem, however, is that the Founding Fathers weren't all Christians. Some of the most prominent members of this group, including Thomas Jefferson and Benjamin Franklin, were actually Deists. They didn't believe that Jesus was God, which is a central tenant of Christianity, and wrote extensively about their Deism. (Refer to Benjamin Franklin: Autobiography, Poor Richard, and Later Writings, edited by J. A. Leo Lemay, and David Holmes's The Faiths of the Founding Fathers for information about this.) There is a lesson in this for both audience and speaker. It's dangerous to accept something just because it sounds true. Credibility can't be established just by saying what the audience wants to hear.