what evidence would they need when God spoke to them audibly? It was one on one discussion.What evidence do you have that God spoke to anyone audibly? (Wouldn't that be "hearsay"?)
If this reference to audible speech is about how the authors of the bible understood what to say or write, then I would refer to the first epistle of Peter which says these men "spake as they were moved by the holy spirit."
One might rightly ask what does that mean or exactly how is that done which would be a good question.
Basically, authentic Christian life (as well as any legitimate pre-Christian spiritual life) involves three spiritual levels:
purification, illumination, and theosis. While purification will be an on going process, it is intended to dominate the period of catechism prior to initiation (i.e. baptism) during which illumination begins to occur. Theosis is divinization, becoming godlike through Christ. (I should say that theosis involves unification which an uncreated energy of God rather than the essence of God which is unknowable both in this life and the next.
Anyway, my point is theosis constitutes the nature of a redeemed man. It is the objective of Christian life. It begins with the energies of the soul interacting with the energies of God Himself. Finally, the body is transformed. This explains the biological phenomenon of holy relics. Those in theosis are the saints of the Church. One must be in a state of theosis to receive revelation from God.
I think the best I can do is refer to others from whom I have learned and who can explain this more clearly and better than I can.
Two Greek writers named Fr. John Romanides and Metropolitan Ierotheos Vlachos have explained this in accordance with Christian tradition. Fr. John Romanides
is an oecumenist, but he understood and wrote very well on this subject. His book 'Franks, Romans, Feudalism, and Doctrine'
is where I first read about this theology. It is also the best historical analysis of western civilization and the most astute refutation of the papacy that I have ever read.http://www.romanity.org/cont.htm http://www.romanity.org/htm/rom.03.en.franks_romans_feudalism_and_doctrine.01.htm
Fr. John Romanides passed away in 2002.
Metr. Hierotheos Vlachos was one of his students who wrote an outstanding basic book of about 100 pages entitled 'Orthodox Spirituality'.
OODEGR is a Greek operated website with a lot of Metr. Vlachos's material and plenty other good things on it.http://www.oodegr.com/english
The three stages of spiritual life are also explained in depth in the Philokalia by Niketas Stithatos:http://archive.org/details/Philokalia-TheCompleteText