The prototype of this experience was the Transfiguration, when Jesus became radiant with inner Light before the disciples on Mount Tabor. Since God is transcendent, Barlaam had argued, his Light would not be visible to earthly eyes. The disciples could not have seen the Divine in the experience on Mount Tabor, and so their vision was symbolic. Gregory was as willing as any hesychast to draw a sharp distinction between the Creator and creation, but he rejected an interpretation of the Transfiguration which would make deification nothing more than a symbolic event promising some future glory. For Gregory, as for Symeon, beholding the Light is beholding the Divine.
Deity indeed transcends affirmation, but it equally transcends negation.
Barlaam saw in the knowledge of God revealed by grace merely an attempt to secure knowledge like that provided by the senses but inaccessible to them. Divine knowledge is not, according to Gregory, merely another science with special criteria for accessibility it is not gnosis, knowledge, but enosis, union or assimilation. The alleged contradiction between the transcendence of Deity and the deification of the human being is in fact a dialectical truth, both halves of which must be understood simultaneously. God rejoices from all eternity in the sublimity of His glory. . . . God lives in this glory that is His own, intrinsic to Him, in perfect happiness above all glory, needing no witness, unable to allow any division. . . .