Daf in Nedarim 38 says that Navi has to be strong, rich, wise, and humble, using example of Moshe.
Many people love quoting the humble part, but it is at the end of the list (others have to be achieved first). This would enable him to convince other people of his message: people will respect him and see that he know things.
This idea also touches on the topic of observant Yidden in Israel influencing the others – not be being weak, poor and uneducated.