Oh, I know exactly what the point is - you can't see what Voegelin sees unless you're predisposed to seeing it by sharing his fundamental worldview. Which is about three millimeters and one fig leaf away from saying that truth is subjective and dependent on perception - truth depends on perception, perception depends on experience, therefore truth depends on experience. No thanks. Putting a tie and jacket on relativism doesn't make it any more palatable to me.
Voegelin is not saying that we have reason via revelation.
Oh, come on - of course he is:
I have spoken of questioning knowledge and knowing question in order to characterize the experience that I have called noetic, for it is not the experience of some thing, but the experience of questioning rising from the knowledge that man's being has not its ground in itself. The knowledge that being is not grounded in itself implies the question of the origin, and in this question being is revealed as coming-to-be, albeit not as a coming-to-be in the world of existing things but a coming-to-be from the ground of being.- Anamensis
Divine reality is being revealed to man in two fundamental modes of experience: in the experience of divine creativity in the cosmos; and in the experience of divine ordering presence in the soul.
The two modes are always structures in man's consciousness of divine reality, but they are not always conscious in the form of reflected knowledge. The experience is the area of reality where the revelatory appeal from the divine side meets with the questing response from the human side, and reflective meditation on the response is preceded by millennia of less reflected response in the form of cosmological symbolization. Only late in history, when man becomes aware of himself, of his spirit and intellect, as an active partner in the cognition of divine reality, will the two modes be discerned and adequately symbolized. Only when the response becomes luminous to itself as a quest for the divine ground, and when the quest becomes an act of reflective questioning, will man find himself moving either in the direction of divine creativity toward a Beginning of things, or in the direction of the ordering presence within his soul toward a divine Beyond as its source.
- The Beginning and Beyond
Both Aristotle and Plato were attune to a source that gets entirely lost in Kant. Nowadays its OK to call it intuition.
You are completely mistating what Voegelin is saying. He is saying that for there to be possible discussion there has to be some common ground. The problem of debating with materialists is that they do not acknowledge even the existence of their own minds. This is totally irrational and therefore any attempt at rational discussion with materialists is fruitless. Your rejection of passages where he describes why intellect is a quality of mankind shows his statement to be correct.