It is often bandied about by those who like to talk about theology, that while most Protestants understand Christ’s saving action to be that of substitutionary atonement (Christ took the punishment that I deserve), Orthodox Christians understand Christ’s saving action as the conquering of death. Most often, the writings of St. Irenaeus are used to support this contention. However, in reality Orthodox Christians are far too apophatic to let themselves be tied into such a narrow, either/or, understanding of a mystery that is beyond human comprehension. Yes, Orthodox Christians talk about the saving work of Christ as conquering death, but within the tradition there are also those who, like St. Paul, use substitutinary language—although this is generally understood metaphorically in reference to Old Testament sacrificial typology.
Another way the Church understands Christ’s work of salvation, a way that was emphasized by St. Athanasius and St. Gregory Palamas (and many others, but these two come to mind immediately) is communicatio idiomatum, exchange of natural properties. According to this way of understanding salvation, in Christ’s incarnation human nature (all human nature) changed. When Christ who is God, one of the Holy Trinity, joined himself to our nature, human nature became infused (by Grace) with divinity. By joining human and divine natures in his incarnation, Christ makes a path and shows a way for all humanity. Thus, for example, Christ’s conquering of death is significant not because Jesus arose from the dead as God , but because as the God-man Jesus arose from the dead. In Christ human nature conquered death; consequently, all human beings also have conquered death.
You might call this salvation by participation. Christ has participated in human nature, so all human nature has (again, by Grace) communicated in or exchanged or participates in the properties of Christ’s divinity. Everything that is Christ’s by nature is ours by Grace because Christ has taken on our nature. In a sense, this is a done deal, fiat accompli. No matter what any particular human being does or does not do, wants or does not want, human nature has been “joined to heavenly things” (as it says in the Divine Liturgy), and this reality influences everything. And yet, each human being also responds to this reality: “And this is the judgment, that the light has come into the world, and men loved darkness rather than light because their deeds are evil. For everyone practicing evil hates the light and will not come to the light, lest his deeds should be exposed. But he who does the truth come to the light” (John 3: 19-21). The light has come. The Grace of God has divinized human nature and those who do the truth come to the light, but those who are practicing evil hate the light.
Each human person is free. Really, it all now comes down to love. Do we love the light or the darkness? One of the biblical and central metaphors of the Christian relationship with God is that of Bride of Christ. And like in any marriage, it takes two to turn hell into heaven. When we love Christ, love the light, following joyfully his commandments, we are happily married to God in Christ. At death, a door opens and all of the passions, temptations, confusions and ignorances that made it difficult for us to fully express our love for Christ will pass away, and the little bit of heaven we experienced on earth will give way to the full embrace of the heavenly bridal chamber. If, however, we have hated the light, if we have refused to come to the light; then death will be a doorway into a hell unlike any imaginable, for all of the entertainments, distractions, excuses and accusations that we have used to shied ourselves from the presence of our loving heavenly spouse will disappear. Then only the light, the light that we cannot hide from, the light that we have hated, will shine brighter than the sun. The hell begun in this life will continue with unimaginable intensity in the next. It’s all a matter of what, or better, whom, we love.