St. Gregory of Nyssa (c. 335 – c. 395), is one of the three Great Cappadocian Fathers along with his older brother, St. Basil the Great, and friend, St. Gregory of Nazianzus.  I especially love Gregory Nyssen for his deep spirituality and mysticism.  He was a highly original and sophisticated thinker who remains controversial among both liberal and conservative theologians to this day.  In his treatise The Life of Moses, St. Gregory tells us that a person’s encounter of the mystery of God corresponds to the three theophanies of Moses, involving successive entry into light, cloud, and darkness.  

According to St. Gregory Nyssen, the first stage in our quest to encounter God is Moses’ vision of God as the light of the burning bush; illuminating the darkness of our sin and ignorance.  The second stage involves a journey from light into partial darkness where Moses encounters God as the ‘cloud’; the intermingling of light and darkness, revealing the distance between the Creator and the created realm. The third and final stage entails Moses entering the darkness of Sinai where God is; and our realization upon encountering and even being united with God that He is utterly incomprehensible in his essence. 

In this treatment, I think, St. Gregory of Nyssa clearly identifies both cataphatic and apophatic theology, bridges the two and holds the tension between them, drawing the best from both.

“What does it mean that Moses entered the darkness and then saw God in it? What is now recounted seems somehow to be contradictory to the first theophany, for then the divine was beheld in light but now He is seen in darkness. Let us not think that this is at variance with the sequence of things we have contemplated spiritually. Scripture teaches by this that religious knowledge comes at first to those who receive it as light. Therefore what is perceived to be contrary to religion is darkness; an escape from darkness comes about when one participates in the light. But as the mind progresses and, through an ever greater and more perfect diligence, comes to apprehend reality, as it approaches more nearly to contemplation, it sees more clearly that God cannot be contemplated. For leaving behind everything that is observed, not only what sense comprehends but also what the intelligence thinks it sees, it keeps on penetrating deeper until by the intelligence’s yearning for understanding it gains access to the invisible and the incomprehensible and there it sees God.  This is the true knowledge of what is sought; this is the seeing that consists in not seeing, because that which is sought transcends all knowledge, being separated on all sides by incomprehensibility as by a kind of darkness. Therefore, John the sublime who penetrated into the luminous darkness [λαµπρός γνόφος – lamprós gnóphos], says “no one has ever seen God,” thus asserting that knowledge of the divine essence is unattainable not only by humans but also by every intelligent creature.  When, therefore, Moses grew in knowledge, he declared that he had seen God in the darkness, that is, that he had then come to know that what is divine is beyond all knowledge and comprehension, for the text says,’Moses approached the dark cloud where God was‘.” 

~ from: The Life of Moses