Romans 12: part 1

1 I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service. 2 And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.

Service (Gr. latreia, lit. “bow down”) is better translated “worship”. This is the worship of God through the whole life of the Church, beginning with a renewed mind and integrity of heart. In union with Christ, we are brought from worshipping the creature to worshipping the Creator in all we do. This worship is:
(1) Physical: Bodies suggests both the physical aspect of human nature and human nature generally – ourselves.
(2) Living: a contrast to the Old Covenant under which sacrifices were put to death. Under the New Covenant, to die is also to be resurrected. Sacrifice is not a final act but the firstfruit, the foundation, for all other spiritual fruit.
(3) Virtuous (holy, acceptable): OT sacrifice was unacceptable and temporary. Animals are not substitutes for humanity or true holiness.
(4) Reasonable, or “spiritual” (Gr. logike): Though worship of God has its logical side, it is more than this – even as Christ, the Logos, possesses reason but is far more than reason. To be reasonable  is to live according to Christ, with renewed hearts and minds.

Faithful relationship to God changes our relationship to the world. (1) We renounce the pretenses of “this present evil age.” Conformed to this world is to be identified with and shaped by the world’s values and pleasures. (2) We are transformed, starting with the inward man, the mind, by virtue, the keeping of God’s commandments. Mind here is more than the rational faculty; it is the highest faculty of human nature: “The eyes of your heart,” by which one sees and comprehends God.

Comment on Nature and Grace by Fr. Maximus on Energetic Procession

The distinction between nature and grace is very easy: nature is created while grace is uncreated. That means that grace is not an effect or habit, but is God’s uncreated energies. So when God grants us His grace, he is not implanting a particular quality in us, but is rather working within us, as we work with Him; hence the concept of synergy, which is impossible on the Latin view in any real sense. If you do not distingush between essence and energy in God your concept of grace will always be extrinsic to the human person, a mere add-on to whatever humans “really” are (unless you choose the other side of the Latin coin, and opt for pantheism).

The basic paradigm you seem to be working from is the division into nature, preternatural gifts, and supernatural gifts, all of which are created. But from the Orthodox point of view, nature can never exist apart from grace: grace sustains and saturates nature, so that God is always working in creation on different levels. The division into natural, preternatural, and supernatural is artificial, because man in his natural state always partakes of God’s grace to the maximum extent possible for him; and even when in his unnatural state he partakes of God’s grace to the extent that he chooses.