I am not trying to prove the existence of God. Nobody can prove that God exists, except to themselves. That is what I tell people I have discussions with. If they ask me why I believe in God, I tell them it is because of the Revelation of Baha'u'llah, but obviously that will only be proof to a numbered few people.The problem is that you cannot bring anyone proof of the existence of God unless they have some basic knowledge.
Whereas that is true, I think in terms of whether they actually received communication from God or not, whether they were sent by God on a mission, in which case they would be a Manifestation of God, a Messenger of God, a true Prophet. Other people can manifest some attributes of God but that does not make them divine. In another discussion about miracles, I posted this quote this morning which explains how a Manifestation of God has special powers:Generally, I think people accepted a person as a prophet, guru, or manifestation of God when they recognize in that person a selfless soul: a person who has realized the attributes of God to the fullest, or purified their consciousness to the fullest. Then this person becomes transparent and through him man can recognize the divine.
“The Holy Manifestations are the sources of miracles and the originators of wonderful signs. For Them, any difficult and impracticable thing is possible and easy. For through a supernatural power wonders appear from Them; and by this power, which is beyond nature, They influence the world of nature. From all the Manifestations marvelous things have appeared.” Some Answered Questions, p. 100