the Works of Dionysius the Areopagite - On Divine Names - Chapter 01 - Section 2

2. Now concerning this hidden Super-Essential Godhead we must not dare, as I have said, to speak, or even to form any conception Thereof, except those things which are divinely revealed to us from the Holy Scriptures. For as It hath lovingly taught us in the Scriptures concerning Itself the understanding and contemplation of Its actual nature is not accessible to any being; for such knowledge is superessentially exalted above them all. And many of the Sacred Writers thou wilt find who have declared that It is not only invisible and incomprehensible, but also unsearchable and past finding out, since there is no trace of any that have penetrated the hidden depths of Its infinitude. Not that the Good is wholly incommunicable to anything; nay, rather, while dwelling alone by Itself, and having there firmly fixed Its super-essential Ray, It lovingly reveals Itself by illuminations corresponding to each separate creature’s powers, and thus draws upwards holy minds into such contemplation, participation and resemblance of Itself as they can attain—even them that holily and duly strive thereafter and do not seek with impotent presumption the Mystery beyond that heavenly revelation which is so granted as to fit their powers, nor yet through their lower propensity slip down the steep descent, but with unwavering constancy press onwards toward the ray that casts its light upon them and, through the love responsive to these gracious illuminations, speed their temperate and holy flight on the wings of a godly reverence.

Dionysius the Areopagite: On the Divine Names and the Mystical Theology. by C.E. Rolt Christian Classics Ethereal Library