Some interesting thoughts about Essence vs Energies

 As seen from the book Deification in the Eastern Orthodox Tradition: A Biblical Perspective (Gorgias Eastern Christian Studies)

"We do therefore have in Jewish theology something which corresponds to the essence-energies distinction of Orthodox Christianity. While on the one hand "face" panim is like the incomprehensible essence, on the other hand the Goodness of God which passes Moses by in the cleft of the rock has affinities with the Orthodox idea of the uncreated energies.

 The glory or kabod is partly knowable and partly unkowable. One might describe it as an uncreated energy, in that it is the manifestation of God to his people in the world, rather than God as he is in himself. Its menacing, or transfiguring, quality, depending upon the state of the recipient, reminds one of the Uncreated Light of God, which becomes a fire to sinners.

 There is also, however, a big difference between the Jewish theology of God's presence and that of the Orthodox uncreated energies. Judaism stresses the uniqueness of Moses. Only Elijah had a comparable experience, repeating the sight of God's glory from the cleft in the rock and finding God, not in the thunder and fire nor by seeing God's glory, but by hearing a gentle voice, in which the Lord was found (1 kgs 19:12). The New Testament perspective is that all human beings may experience the divine glory, through faith in Jesus Christ and the operation of the Holy Spirit. In the Old Testament, Moses acts as an intermediary between God and his people, standing between them and God. Christ's mediation is different. In the Incarnation, the human nature has been brought into union with the divine nature. If we are "in Christ," then we come into union ourselves with the divinity through our union with the Union27 of God and Man in Christ. Biblical Judaism had a different idea of deification, that is, the imitation of God by following his commandments, commandments that reveal something of God's nature." [1] 

 "The Jewish theology of revelation is very similar to that of Eastern Orthodoxy. In both, the nature is unknown but God is known by his energies. Moses Maimonides (1135-1204) summarizes the knowledge that can be had of God:

 That first and greatest of all thinkers, out teacher Moses, of blessed memory, made two requests and both his requests were granted. His first request was when he asked God to let him know His essence and nature; the second, which was the first in point of time, was when he asked Him to let him know His attributes. God's reply was to promise that He would let him know all His attributes, telling him at the same time that they were His actions. Thereby He told him that His essence could not be apprehended in itself. But also pointed out to him a starting point from which he could set out to apprehend as much of Him as man can apprehend. And indeed Moses apprehended more than anyone ever did before him or after him..29

 In imitating God, the Jew imitates the divine energies and so becomes like God in behaving as God does. As Moses Maimonides epitomizes his tradition:

 "The highest virtue to which man can aspire is to become similar to God as far as this is possible; that means that we must imitate His actions by our own. 30

 God's Holiness is itself an energy, since it describes God's priestly activity of setting apart a people and giving them the means of becoming holy themselves:

 "You shall be holy to me, for I the Lord am holy and have separated you from the peoples that you should be mine."(Lev 20:26) 

 The difference between Christianity and Judaism is often described as Jewish legalism versus Christian freedom. However, this is a distorted perspective. Legalism is possible in all religions, including Eastern Orthodox Christianity, ........etc" [2] 

 Deification in the Eastern Orthodox Tradition: A Biblical Perspective (Gorgias Eastern Christian Studies)

 [1] page 119, [2] pages 121-122 by Stephen Thomas from the book "Deification in the Eastern Orthodox Tradition: A Biblical Perspective"