I have always believed that the soul, once created, has immortality by virtue of what it is. When one dies, and after the final judgment, one either perpetually degenerates endlessly towards nothingness or goes "further up and further in" (to use Narnian language) toward God indefinitely.
I don't see any reason why I would have to hold a platonic belief in the pre-existence of souls in order to justify my belief that the soul is intrinsically immortal once it is created. I don't see any prima facie reasons why it would be incoherent to say that once man is born his soul will never go out of existence. He is immortal by virtue of what he is - made in the image of God.
Well, tonight, for the first time ever, I came across a friend of mine who has always taken for granted the very opposite belief as I have just explained. Then I found that another friend believed just the same as him. These two guys are both Eastern Orthodox, if it helps understand where they're coming from. I am, well, having a Christian identity crisis at the moment. I'm moving toward Orthodoxy. But anyhow.
To put his belief simply, we are only immortal - whether we end up in heaven or hell - in virtue of the fact that Jesus became flesh. I have never heard that before. The proof text provided was not sufficiently clear or precise on the matter.
I am, of course, familiar with the idea that Christ vanquished death. But that we would have without the incarnation, simply slipped into literal and actual non-existence, seems to me absurd! I don't see any reference in Scripture or other writings (that I know of) pointing to a place in Scripture where this is suggested. I've always understood Christ conquering death to refer to save us from the gradual but unending descent into eternal hell that would have been all our fates had Christ not made a way. But my friends were suggesting that it is just apparent that this conquering of death refers to the fact that without Christ's incarnation every single one of us would eventually stop existing one day. So, according to my friends, the implication is that an eternal hell would not have existed without the incarnation of Jesus. This is something I've never heard before either.
I have to say, I'm really confused.