This summer a friend asked me a great question about how Evolution and Original Sin can relate to each other. To get to my answer, I must first do a little theological back filling to set the stage for the question. First, I accept evolution as the means by which God "creates" life, although I would prefer to say that evolution is the self-expression of infinite Divine potential in space and time. If I were to bet, I would bet that the universe is actually a multiverse, in which every universe exists that can actualize at least one unique good as it evolves. This seems to be the kind of reality that would best actualize God's infinite possibility, although what I'm about to say would work in a singular universe as well.
Most of the great world religions state that Ultimate Reality-- often understood as a Infinite, Transcendent, Immanent, Personal "God"-- is characterized by love, compassion, empathy, and a self-emptying nature. God pours Godself out to share the gift of life with others. The unitive Divine Being allows Godself to become multiplicity to enjoy the actualization of Godself in the lives of countless beings. Thus the unfolding cosmic process of evolution is God giving Godself to create a world of beings who will someday realize they come from Divine Love and they will return to Divine Love.
In the process of evolution, the dice seem to be loaded to make the system trend toward the emergence of conscious, creative, communicative persons. In my theology, persons are unique in that they can be consciously aware of fellowship with God, and consciously choose to enact or reject that fellowship.
Most creatures in the world operate on instinct and are not fully conscious or sentient in the way human persons are (I don't think humans are the only persons, but we are the only persons we currently know). What I mean is that when most creatures act or feel pleasure or pain, they are not really different from a rudimentary computer algorithm or robot: They enact pre-programmed commands, and their sensors go off in response to stimuli. They don't have meta cognition to think about what they think about. They don't tell stories. They don't ask why. They don't invent things. They don't create art.
But as evolution continues, persons emerge who do all of these things. We can see this process happening right now in some higher animals such as chimps and dolphins, although they are not fully personal yet. Perhaps some day we will see it happen with a computer program. But AI has not arrived yet.
When this qualitative transition fully occurs from instinctual creature to conscious person, our mental apparatus is able to tune into a new level of reality: The level of moral and aesthetic value. Prior to the transition to person, creatures think in terms of actuality and potentiality (is/is not/can/cannot). After this transition, the moral light enters into consciousness: Should/Should not. The idea of moral duty and obligation. The rudimentary ideas that love, compassion, empathy, honesty are moral goods we ought to do, while hatred, selfishness, ruthlessness, and deception are moral evils we ought not to do (at least not to our own kinship group, although as persons evolve this moral awareness universalizes).
Along with this moral awareness comes an awareness of the future, and of the finality of death. While higher animals may mourn the loss of close members of kinship groups, sentient persons not only mourn the loss of loved ones, but they pre-mourn their own loss in the future as well. They begin to develop theories about the afterlife and take steps to ensure the continuance of their memory/legacy. Death takes on meaning, and serves as a kind of ominous warning about the consequences of action. Careless and stupid actions begin to be causally related to death.
So, among the many transformations of awareness for persons-- from developing an aesthetic sense to developing rituals of worship-- perhaps the greatest transformation is that we gain the dual sense of morality and mortality. And this directly and finally leads us to answer your question.
Among the many instincts that are inbuilt into the successful higher animals is the drive to predation/hunting, as well as the drive to cooperation/herd behavior. Each of these opposite instincts are useful in some situations, and are part of the biological inheritance provided for us by evolution. But when creatures evolve into persons, they suddenly have the moral choice between predation and cooperation beyond instinctual obedience. There becomes a moral sense that predation can be good only in a very limited context, and cooperation is generally good in most human contexts. And yet there is also the awareness that predation can provide access to resources and sex, at the cost of human community, by disobeying this moral sense. And there is also the sense of real danger that comes from violating this moral sense: Betraying the community for short term gain can cause ostracism, punishment, or even death.
And yet, this awareness of morality and mortality is not just limited to specific situations and the utility of individual choices. It somehow FEELS universal: As if betraying the moral ought also leads to death in a deeper "spiritual" sense. Perhaps you might think of this as self-alienation: Killing a little piece of yourself as you do what you yourself do not agree with. Or perhaps it goes even deeper and somehow alienates us from a Divine Cosmic Source (which, of course, is what the great world religions affirm in their various ways).
So, the "original sin" would be when our first personal ancestors became aware of morality and mortality, and yet acted against their own moral sense, incurring upon themselves the "death" of personal shame and social destruction that always accompanies choices that we condemn in ourselves. This "original sin" transmits like a virus or a meme through society. People pick it up by nature AND nurture as society evolves and develops.
I think that this is what Genesis chapters 1-11 are expressing, using poetry, myth, and symbolism. I would reject a "literal" reading of these Scriptures as self-contradictory, anti-science, and literarily absurd. But clearly in a allegorical or mythopoeic way, these chapters point to deep truths about the self-alienation and divine-alienation that comes from morality and mortality.
In this, I side with the Eastern Orthodox tradition on "original sin": They have always viewed it as an infection which makes people sick from generation to generation, which needs to be healed by the medicine that is God's grace given through the great Physician Jesus Christ. They have never had time for the peculiar Western ideas that legal or moral "guilt" was transmitted through the generations, so that modern people bear the "guilt" for "Adam's fall". In fact, the personal angst to feel guilt for what others do is one of many symptoms that we are infected with the disease of sin, and need healing and liberation. And the Western idea that original sin is somehow connected with the act of sex, thereby making sex dirty and unnatural, is completely absurd and probably demonic. To be sure, sexuality used wrongly in a predatory way that uses others, is sinful. But that is a case of using sex badly, not of sex in itself being bad.
Western theologies have made an idol of the courtroom and the financial transaction. They see God as arbitrarily commanding laws, and attaching a "price" to obedience or disobedience. When we make just one infraction against the command of the infinite being, we thus incur an infinite debt, which we must repay with infinite punishment. And then Jesus is seen as the cosmic whipping boy who takes the infinite punishment we "deserve" from our cosmic abusive Father, so that we don't have to pay. Western theologians call this act of divine payment "grace", since we cannot have salvation except for a free gift of Infinite worth paid on our behalf. But there is another way to look at it: As an absurd, unjust, and capricious God who is divided against Himself and who must punish Himself in Christ to pay for the guilt he demanded.
Does disagreeing with Western Theology equate to Pelagianism? I think not. Pelagianism is the denial that we need God's grace to be saved and healed: We can "do it ourselves" without God's help. But I would rather say that all is grace. The fact that we live in an evolving creation is because God graciously empties Godself into the cosmos to actualize the Divine Life in space and time. The freedom and consciousness with which we exercise moral choices are likewise gifts of grace, along with our twin awareness of morality and mortality. When we are infected by sin, it is grace that calls us back to God, grace that heals us, grace that empowers us to choose the good.
Ultimately, as a Christian-- and this in no way takes away from the many ways God's grace is displayed in other religions-- the ultimate act of Divine grace is that God's self-consciousness becomes personally embodied in the human life of Jesus of Nazareth. In Jesus, God personally enters into solidarity with our human problem of morality and mortality. He perfectly embodies the good-- fulfilling our problem of morality-- and he takes death into himself and overcomes it by the resurrection-- fulfilling our problem of mortality. In so doing, he becomes the "injection point" of God administering the cure for our infection. By uniting God's life and human life in himself, Jesus opens the gateway to be united to God by sharing in his life. Our "therapy program" is to daily choose to imitate Christ and invite his life to flow through us. This is all grace and in no way Pelagian, although it is also not passive. We actively cooperate with the Christ life working through us, and the very possibility of cooperation is because grace is working through us.
Now, the same Divine life that becomes personally embodied in Christ, is also the same Divine life that teaches us in Krishna, shows us the path to enlightenment in the Buddha, establishes Confucius' Mandate of Heaven, expresses itself in the Tao, declares itself one in Allah, and calls to Moses in the burning bush. It is the cosmic Logos-- Word, Purpose, Plan, Pattern, Message-- that has shined light on all people and which has taken on flesh in Jesus (cf. John 1:1-18). So, I don't think that participating in Christ's life is limited to the Christian Path, although the Christian Path is certainly the most explicit and often the most direct way to participate in Christ's life.
But in terms of morality and mortality, Jesus Christ represents the final goal of human evolution, occurring early in human history, to show us what we can become if we cooperate with the Divine Spirit working within us. We are made to fully unite divinity and humanity in ourselves just a Christ did. As Saint Athanasius said in the early 4th century: The Divine Son became human so that humans may become divine. We are made to be gods who reflect God in our consciousness, creativity, communication, and compassion. Original sin is the disease that tries to trick us into NOT evolving into the glorious children of God that we are meant to become. But by cooperating with the Christ life that is at work in what is best in great religious paths of the world, we can be healed of this disease and play our role in humanity's evolution into Christlikeness.
Thanks for reading my incoherent babble. May strength and compassion and wisdom fill your life. // Nate.