Essence and Energies
The opposing poles of Orthodox theology, that of cataphasis versus apophasis, can be best revealed within the Orthodox distinction between the essence and energies of God. Our cataphatic knowledge of God comes from our explanations of the energies of God, while our apophatic knowledge of God stems from our stating of what God by nature is not, what the essence of God is not.
The Orthodox distinction between the essence and energies of God is one that is not found in the western churches. God is ineffable, yet is simultaneously knowable in the person of Jesus Christ. We can participate in the divine nature of Christ, knowing God through our experience and exposure to the myriad energies of God; yet, of the nature of God, of the inner being of God,this we cannot know. The energies of God permeate the whole of creation, yet God is also outside and apart from all things according to His essence. Yet, “we know his essence through his energy,” Saint Basil affirms, and “No one has ever seen the essence of God, but we believe in the essence because we experience the energy.”1
These energies of God are God himself, and we cannot see them as apart from God, or something created from God, for “the Godhead is simple and indivisible and has non parts. The essence signifies the whole God as he is in himself; the energies signify the whole God as he is in action.”2 It is this distinction that separates God as ineffable and wholly unknowable in his fullness, yet simultaneously opens the door for our mystical participation and union between man and God in our process of theosis, or deification. It allows for a union between man and God, yet does so without a confusion of persons, and without a confusion of natures. This distinction does not destroy the divine simplicity of God, nor confuses or divides the divinity of God, for the essence and energies are both divine and equally God and uncreated:
“It is said that God has essence and energy and that this distinction does not destroy the divine simplicity. We confess and believe that 'uncreated and natural grace and illumination and energy always proceed inseparably from this divine energy' And since, according to the saints, created energy means created essence as well . . . God's energy is uncreated. Indeed the name of divinity is placed not only upon the divine essence, but 'also on thee divine energy no less'. This means that in the teachings of the holy Fathers, 'this (the essence) is completely incapable of being shared, but by divine grace the energy can be shared.”3
“Anyone who tries to describe the ineffable Light in language is truly a liar - not because he hates truth, but because of the inadequacy of his description.”4 Yet, we make use of various analogies to try and come to a rational understanding of that which is beyond rationality and definition. The early Fathers often used analogies of the sun in their description and explanations of both the Trinity, and the distinction of essence and energies. In this case, the sun itself is the essence of God, and the light and heat it emanates are the myriad energies of God. We can participate and experience the energies of God, but if we were to fly into the Sun, we would be destroyed.
We cannot know God in his essence, but we can know him and experience him through his creation, the living psalter singing to his glory, honor, and majesty. It is the goal and purpose of every human being to incarnate the living God in their own lives, and through the gradual process of theosis, become living conduits of His energies,becoming a tool through which the love of God can work and manifest itself by incarnating Christ within our lives.
 - Kallistos Ware. The Orthodox way - Basil
 - Kallistos Ware. The Orthodox way
 - Bishop Hierotheos Vlachos, Orthodox Psychotherapy: The Science of the Fathers (Levadia, Greece: Birth of the Theotokos Monastery, 1994.)
 - Saint Gregory of Nyssa