Here is my attempt to summarise this idea which I have just been exposed to in reading the book quoted below by Stephen Turley:
Epektasis is from Paul in Philippians 3:13 (translated ‘reaching’ in some versions), the idea seemingly developed by Gregory of Nyssa to describe our desire (reaching) to be filled with God’s infinite, unceasing beauty (glory, perhaps one could say light or brightness as well?), therefore for that desire to be fulfilled in God, and the fulfillment of the soul’s desire for perfection (?). After the soul is filled with some of this glory, the satisfaction draws us to desire even more of it (since God’s glory is infinite, it can do this), and we keep desiring, hoping, in a constant eros for God, a desire for union with Him Who is the Giver of our being and beauty, and the Giver of the being and beauty of all of creation. We want to be united with the Source, to gloriously enjoy the richness, comfort, excitement of that Source.
Hence, for Gregory, this epektasis, this eternal traversing of God’s infinity, involves an eternal communion with the God revealed in Christ, who is the self-replenishing fountain of love and delight, an infinite sea of absolute Beauty.
- from Awakening Wonder: A Classical Guide to Truth, Goodness and Beauty by Stephen R. Turley, PhD
This is the thing I have felt as desiring to get into beauty (I believe I got this phrase from C. S. Lewis's The Weight of Glory), to somehow pass through that barrier between the tantalising experience of something beautiful and the actual beauty itself.
