Do you know how some people can do anything?” “What do you mean?” “I mean, you tell them to write a tune, they give you a symphony right there. You tell them to write a book, they write you a novel in a day. You tell them to move a spoon without touching it, they move it. If they want something, they make it happen. Miracles, almost.
It used to be said that when the Baal Shem Tov came into a town, his impact was so strong, he didn't have to speak. His disciples had to dance or to sing or to preach to have the same effect. I think a real messenger, myself or anyone, by the very fact that he is there as a person, as a symbol, could have the same impact.