So, in using that logic you've touted so highly (I remember an LDS missionary once chiding me for using logic in my response to his proselytizing attempts), the implication of your post to which I responded is that if someone makes some very powerful and authoritative statement, that proves it to be true?
Thank you for that example of circular logic.
"Hi, I'm God."
"Why should I believe you?"
"Because God would never lie."
"Wow, I'm convinced!"