Edwards’s definition of true grace falls into two basic halves: it is a communication and participation in divine fullness. … The definitions of these terms are not difficult. … Their meanings converge around the idea of sharing something between parties.
Jonathan Edwards and Deification: Reconciling Theosis and the Reformed Tradition, by James R. Salladin
Definitions are always a little more difficult than this, as words can have slightly different meanings to different people, or mean something different within different cultures, traditions, times. So, what is meant by these words for Edwards?
Generally, “communication,” while holding several possible meanings, generally emphasizes the act of giving; to “communicate” is to give something that is to be shared. Likewise, “participation,” while holding several possible meanings, generally emphasizes the act of receiving, or participating in, or partaking of that which was shared. “Communion” should also be understood. Again, while holding several possible meanings, communion generally emphasizes this mutual act of sharing and receiving – “fellowship” might best describe Edwards’ usage.
These definitions are helpful because they show the three concepts to be three distinct roles in the same dynamic….
Salladin will follow custom: when referring to the entire dynamic, he will simply use “participation.” If he is being specific regarding the giving or receiving, this will be clear in the context (and I hope I can keep it clear) and then he will use “communication” and “participation,” respectively.
Edwards considers grace – true grace, or special grace – as a communication and participation in divine fullness. So, what does he mean by this?
Western Christian theology produced (at least) two lineages of participation thought. The first grew out of Christian engagement with Platonism: How does creation derive being from “eternal realities”? This lineage can be identified with the term “methexis.” The second lineage of participation thought is more relational: “intimacy and differentiation, not consubstantiality.” Not quiddity (not the same essence), but union where the distinctions remain. This lineage can be identified with the term “koinōnia.”
Both of these terms can translate to “participation,” but they should be considered as meaning two different things. Within Edwards’ thought, he is using participation in the second sense: relational, with intimacy and differentiation, but not sharing the same essence (quiddity).
Recall this framework of Edwards, presented earlier:
1) Special or true grace is a communication and participation in divine fullness.
2) Divine fullness is not latent within created nature’s ontology.
3) Created nature has no native capacity to acquire divine fullness.
4) Divine fullness is something of God’s own good and something of God himself.
5) Divine fullness is not the divine essence.
6) Divine fullness is given immediately to the creature by God.
7) Special or true grace, or the communication and participation in divine fullness, achieves mutual indwelling between God and creature.
The first three points make clear that Edwards is not suggesting that a thing gains quiddity within his discussion of divine fullness. Point two makes clear: divine fullness is not something latent within the being, that he can develop through his own efforts. Yet, the being can remain a fully ontologically stable being without ever partaking in this divine fullness. Point three is clear: the being has no means on his own by which to obtain divine fullness.
While point four offers that divine fullness is something of God, point five makes clear that whatever this “something of God” is, it is not His essence.
This denial that participation in divine fullness establishes quiddity also provides an important positive clue in uncovering what sort of participation Edwards intends. Whatever this participation means, it will necessarily preserve ontological differentiation.
In the language of the Eastern Orthodox, this is (or at least is close enough to) the essence-energies distinction. Each of the creature’s quiddity and God’s quiddity remain intact, neither impinging on the other’s quiddity, or essence.
So, are we left with an impossibly wide ontological barrier between Creator and creature? No. Point six bridges this chasm. Divine fullness is given immediately by God. By “immediate,” it is meant that grace is given “not by the intervention of natural causes.” There is no third entity, no natural intermediary. It is given from Creator to creature.
The divine and the natural relate without mediation other than God himself.
Point seven brings it all together. Call it deification, divinization, theosis. A mutual indwelling between God and creature. The culmination of special grace is mutual indwelling, yet God and creature remain distinct.
In this, Edwards follows John Owen closely. The notion of communion in both of these men is personal, social, and relational. Owen defined this communion as…
“…the mutual communication of such good things as wherein the persons holding that communion are delighted, bottomed upon some union between them.”
The direction of travel makes clear that this participation is communicated, or given immediately, by God. It is not achieved by the creature, but is something received by the creature. God gives, or “communicates”; the creature receives, or “participates.”
Conclusion
2 Corinthians 13: 14 The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Spirit be with you all. Amen.
This asymmetry remains – the creature’s reception and indwelling are always dependent on the ongoing communication of God.
Once this fullness is given (communicated) and received (partaken of), God and the creature share (communion) in mutual indwelling.


I find this series very engaging and invigorating. Perhaps Edwards shows we will find that the unity of the Church will progress if we stop letting our theological silos impair us.
"While point four offers that divine fullness is something of God, point five makes clear that whatever this “something of God” is, it is not His essence."
I think this is something like the distinction between our immortal soul and God's divine essence. Our soul is not God, but it is an eternal gift from God that allows us to participate with Him.
"The culmination of special grace is mutual indwelling, yet God and creature remain distinct."
If theosis is mutual indwelling while remaining distinct, I wonder how this relates to the following passage in the Gospel of St. John:
"16. And I will ask the Father, and he shall give you another Paraclete, that he may abide with you for ever. 17. The spirit of truth, whom the world cannot receive, because it seeth him not, nor knoweth him: but you shall know him; because he shall abide with you, and shall be in you. 18. I will not leave you orphans, I will come to you. 19. Yet a little while: and the world seeth me no more. But you see me: because I live, and you shall live. 20. In that day you shall know, that I am in my Father, and you in me, and I in you." - John 14:16-20
Here is Jesus talking only to His Apostles or to all Christians? If He is talking to all Christians, then we must observe the following: the Holy Spirit shall be in us, Jesus is in the Father, we are in Jesus, and Jesus is in us. It might follow that the Holy Spirit is our guide (Paraclete) to help us establish participation/communication with Jesus. And since Jesus is in the Father, we also are in the Father.
How does this discussion of theosis relate to St. Mary and the Greek word "kecharitomene" (used only once in the Bible), which means one who is and will always be full of grace? Was she in a perfect state of theosis?