Apophatic theology - also known as negative theology - is a theology that attempts to describe God by negation, to speak of God only in absolutely certain terms and to avoid what may not be said. In Orthodox Christianity, apophatic theology is based on the assumption that God's essence is unknoweable or ineffable and on the recognition of the inadequacy of human language to describe God. The apophatic tradition in Orthodoxy is often balanced with cataphatic theology - or positive theology - and belief in the incarnation, through which God has revealed himself in the person of Jesus Christ.
Apophatic descriptions of God
- From Scripture
- No one has seen or can see God (John 1:18).
- He lives in unapproachable light (1 Tim. 6:16).
- His ways are unsearchable and unfathomable (Job 11:7-8; Rom. 11:33-36).
- By Saints
- The true knowledge and vision of God consists in this - in seeing that He is invisible, because what we seek lies beyond all knowledge, being wholly separated by the darkness of incomprehensibility (The Life of Moses, Gregory of Nyssa).
- God is infinite and incomprehensible and all that is comprehensible about Him is His infinity and incomprehensibility (On the Orthodox Faith, John of Damascus).
History and Development in the Eastern Church
One of the first to articulate the theology in Christianity was the Apostle Paul, whose reference to the Unknown God in the book of Acts (Acts 17:23) is the foundation of works such as that of Pseudo Dionysius. This is as Pseudo Dionysius so describes. The Cappadocian Fathers of the 4th century, exemplars of this via negativa, said that they believed in God, but they did not believe that God exists, at least in the same sense that man exists (notwithstanding the Incarnation). In contrast, making positive statements about the nature of God, which occurs in most other forms of Christian theology, is sometimes called cataphatic theology. Adherents of the apophatic tradition hold that God is beyond the limits of what humans can understand, and that one should not seek God by means of intellectual understanding, but through a direct experience of the love (in Western Christianity) or the Energies (in Eastern Christianity) of God. Apophatic theology can be also seen as an oral tradition. "It must also be recognized that "forgery" is a modern notion. Like Plotinus and the Cappadocians before him, Dionysius does not claim to be an innovator, but rather a communicator of a tradition." 
Apophatic theology played an important role early in the history of Christianity. The Three Holy Hierarchs all emphasized the importance of negative theology to an orthodox understanding of God. Later John of Damascus employed it when he wrote that positive statements about God reveal "not the nature, but the things around the nature." In addition, Maximus the Confessor maintained that the combination of apophatic theology and hesychasm - the practice of keeping stillness - made theosis or union with God possible. All in all, apophatic statements are crucial to much theology in Orthodox Christianity; the opposite tends to be true in Western Christianity, though there are a few exceptions to this rule.