I have been having a friendly discussion (not a debate, thank God) on whether or not the Orthodox teaching on theosis is just another way of talking about the Roman Catholic dogma of purgatory. It is sometimes attributed to “Byzantine”/Eastern Rite Catholics that differences on these things are a question of semantics. Nothing could be further from the truth.
The problem here is that there are at least two radically fundamental differences with which to begin discussing this topic: the nature of God and, concomitantly, the nature of salvation. Apart from some understanding on what’s at stake with these differences one cannot really begin to address whether or not St Mark of Ephesus’ answer to the Florentine prelates does or does not address whether Orthodox believe in purgatory as Roman Catholics believe in purgatory. Of course, individual persons and scholars will nuance this or that aspect of these concepts, but in general the differences play out along these general lines.
Our reason cannot reach to God’s nature. We can put limits on our ignorance (God is omnipotent–there is no one and nothing more powerful than God; God is omniscient–there is no one and nothing that is unknown to God; God is omnipresent–there is no place where God is not; God is omnibenevolent–there are no words or actions of God except of love; and so forth). But we cannot precisely say what God is, even by his divine revelation (“God is love”), and such revelation only magnifies and intensifies our ignorance. This is especially true when we describe God, rightly, as one.
In the Orthodox understanding of God, what is properly basic to our understanding is the Three Persons of the Godhead. Only in the relations to and with and the activities of these Persons is God known to us (including God’s revelation of himself). Thus, we start with the revelation of the Person of the Father, who begets the Son, and by whom the Holy Spirit proceeds. We are careful to maintain these Personal distinctions, for if we conflate them (say by adding the filioque to the Creed) we distort the revelation of the tri-personality of God.
This is why, in Orthodox living, theology is properly and primarily prayer. God is known first and always through the heart. We do, of course, use reason to articulate the Gospel and our beliefs about God that are true to that Gospel. But such reason is secondary to the experience of the Persons of the Holy Trinity as we pray to God and experience his life.
It is this experience of the life of God that forms the basis of the Orthodox understanding of salvation as well. Orthodox do not, of course, deny that juridical metaphors of legal categories are used in Scripture to describe aspects of our salvation. But we point to the fact that frequently in the Gospels the word for “to save” (sozein) is often also used to describe healings. And for the Orthodox, salvation is fundamentally about the healing of the human person, body and soul, from the ravages of death, mortality, and the personal sins we commmit.
Because we think in these terms, the Roman Catholic dogma of purgatory, with its system of merits, superabundance of merits, indulgences of time and so forth–that is to say, with its basis in a metaphor of legal transactions–is foreign to the Orthodox way of understanding. More to the point, foreign to the way of Orthodox living.
But let us first describe more clearly the differences between the understandings of the Godhead. In the Orthodox way of life, the Trinity of Persons is the primary focus of our life and theology, while at the same time confessing these three Persons to be One God. It is the paradox of the union of the many and the one, which has bedeviled pagan philosophy for millennia. However, in the West, while having this inheritance of theological understanding of the Godhead, there was a turn with the filioque toward a focus on the nature of God; i.e., on the oneness of God.
We can appreciate that the filioque was in some ways an attempt to preserve the divinity of Christ against the Arian heresy. The problem is that the filioque did not have the consensual approbation of the entire Church, and lacking such oneness of mind failed to discern the problems with such an assertion. Despite warnings from St. Photios and others, the Western church went forward and insisted on the addition of the filioque to the Creed, and in so doing, conflated the Persons of Father and Son in an act of nature. In so doing, a rift was rent within the Trinity as Father and Son shared an activity that was not shared by the Holy Spirit. If that which is shared by the Persons of the Trinity is common to their nature, then the sharing of the causing of the procession of the Holy Spirit from both Father and Son meant that the Father and Son shared a nature that the Holy Spirit did not. In focusing on the nature of God, albeit in attempting to preserve the divinity of the Son, Rome diminished the Trinitarian understanding of God.
If this is so, if God is ultimately reduced to a single nature, and if God’s nature remains utterly inaccessible to human beings, then, unless God fails to be utterly other than human beings in his nature, God is inaccessible in principle to human nature. God remains ever distant from human fellowship, declaring this or that person righteous, but otherwise removed. This creates significant problems of Christology as well.
Given this, then, in a legal metaphorical framework, whatever activities abound, these are essentially external to God, who through his vicars, pronounces this or that legal indemnity satisfied. But in this process there is no relational communion with God. Indeed, this is quite the point: these sins must be legally purged and satisfied before one can have communion with God. One passes through purgatory before one can enter into the beatific vision. (I’m painting with broad strokes here, so I beg the indulgences of those who may wish rightly to quibble with particulars.)
However, within the Orthodox understanding, salvation (healing) occurs because God gives us his life. We share in the love of the Persons of the Holy Trinity between themselves (cf. John 17:20-26). It is the sharing of this divine life, this co-participation in that life, which heals our mortality and sin. Just as the man of Nain was raised from the dead and Jesus could not be ritually unclean from contamination with the dead (his life gives life), so, too, when we partake of his life that life cleanses us from sin and death. We participate in, as the saint put it, “the medicine of immortality.”
It is here that it is necessary to at least state, if we cannot properly describe, the uniquely Orthodox teaching on the distinction between the essence (nature) of God and the energies (from energeiai or activities or being-at-work) of God. God’s essence is incommunicable to his creatures, we cannot know it, it is ever infinitely beyond our comprehension. But God’s energies are, in a way, super-abundant, and expresses the Person of God to and for his creatures. A crude analogy: as the nature of our husband or wife is eternally mysterious to us (however much we have experienced the unique union of “one-flesh” with them), they are known to us, and we to them, in the expressions of their nature via their personal words and deeds and the manner in which they are in the world. We cannot have access to their essence or nature as we are always ignorant of such. But we can have communion with them in their energies, in the unique ways of living and speaking and moving and being in our worlds. This begins to offer some analogy to what the Orthodox understand of God’s essence and energies.
One may perhaps put it crudely that for Roman Catholic Christians, salvation is the desire for legal satisfaction; while for Orthodox salvation is the desire for well-being. Indeed, eternal well-being.