Hamartiology - The Orthodox View of Sin
At the fall of man in the Garden of Eden, Adam and Eve both failed to stay within the boundaries set for them, both failing to obey the commandment to not eat the fruit from the forbidden tree, the tree of the knowledge of good and evil. This single act of disobedience served as a nonvocal rejection of their vocation to manifest the fullness of their humanity, to incarnate within themselves the fullness of their human existence. They separated themselves from God as a result of this choice of will, now stricken with a disease of spirit to which the end is death, and sin is but the symptom. “Sin reigned through death,”1 and thus became an unnatural antithesis to God, who is Life. Death is just the unnatural result of turning away from God, and it is this curse we now all bear.
We already understand sin as missing the mark, and that mark being Christ, the fullest expression of humanity to which we were all created for. Yet, there is contrast of views between the Orthodox Church and much of Western Christianity following an Augustinian theology. Though, even this may vary depending on who you ask. Yet, the Orthodox do not believe that any degree of guilt is passed on to the progeny of the sinner, but that each person is responsible for their own sins. So the term Original Sin, at least from the understanding of the Orthodox position, simply refers to the first sin, that of Adam and Eve’s, which created the condition of our fallen nature. The passing on of this condition, this disease down through the generations, is what we refer to as Ancestral Sin. We bear the corruption of Adam’s sin, but not his guilt, and the sins we commit are but a symptom of this disease.
Heaven and Hell
The topic of sin can hardly be discussed within the confines of western Christianity without also discussing the resulting eternal destinations of those in sin. Perhaps it is fitting also that this topic follows shortly on the heels of topic of creation, for much of mainstream Christianity holds to hell as a place created for the sake of punishing those who have sinned against him. It is described as a lake of fire, and in other places as a separation from God. Yet, there is no place that God is not, and nothing that He has created is evil or lacks that qualifier of being good. As such, the Orthodox do not view hell with a caresian location within the spiritual realm, but just as sin is personal in nature, so is heaven or hell for each individual in the presence of the Lord.
I would argue that the contemporary understanding of hell came from the middle ages, and is often attributed to literary works such as Dante’s Inferno for shaping the modern conception of hell, but such ideas of hell were not what the early Church held. Hell was viewed more as a spiritual state within the presence of God, affected by the degree of sin to which we have not repented from. St. Symeon the New Theologian writes:
God is fire and when He came into the world, and became man, He sent fire on the earth, as He Himself says; this fire turns about searching to find material — that is a disposition and an intention that is good — to fall into and to kindle; and for those in whom this fire will ignite, it becomes a great flame, which reaches Heaven. ... [T]his flame at first purifies us from the pollution of passions and then it becomes in us food and drink and light and joy, and renders us light ourselves because we participate in His light.”2
Saint Isaac the Syrian also writes:
"... those who find themselves in hell will be chastised by the scourge of love. How cruel and bitter this torment of love will be! For those who understand that they have sinned against love, undergo no greater suffering than those produced by the most fearful tortures. The sorrow which takes hold of the heart, which has sinned against love, is more piercing than any other pain. It is not right to say that the sinners in hell are deprived of the love of God . . . But love acts in two ways, as suffering of the reproved, and as joy in the blessed!"3
We shall all come before the face of the lord when we fall into the sleep of peace, but how we perceive the countenance of his divine light will wholly depend on our manner of life in this world. Prayer and repentance, charity and almsgiving, love and humility, all these things are necessary exercises of virtue that strengthen us against our spiritual affliction. As vitamins are beneficial to the body, likewise is the exercise and strengthening of virtue beneficial to our soul. It is the spiritually active and efficacious child of God who remains strong in spirit, strong against the symptoms of our spiritual illness, and worthy to receive the crown of everlasting life to those who love Him.
Sin is a symptom of a spiritual disease that afflicts mankind, and that disease is Godlessness. As a man sick with cold or flu cannot help himself in fits of sneezing, coughing, fever, and aching of body, so can we not help ourselves when we fall into sin. We believe that sin can be voluntary or involuntary, conscious or unconscious, yet it is always personal in nature, for which each of us are responsible for our account and repentance of them. Likewise, as we cannot be mad at him who exhibits the symptoms of his illness, neither should we be mad at he who sins. We should forgive as freely as we would wish to be forgiven, for it will be by that same scale with which we will be judged.
While there is no cure for this disease, in so much that we will all eventually die, we can be cleansed, and our self inflicted wounds be salved by forgiveness given from repentance. Indeed Christ forgives us for our sin, cleansing us for the wedding banquet, making us worthy of the wedding garment received at baptism. He does not remove the disease, our sinning problem, but simply opens the door for us to return home to paradise in the eternal rest in the presence of our LORD. But first we must open the door of the Church by putting on the garment of baptism, where we are first cleansed of our sins and made ready for the banquet, the Mystic Supper.
To borrow the words of St. John Chrysostom, the Church is the hospital for the soul. It is here that we address the maladies of the spirit. The Priest is the spiritual surgeon, confession his scalpel and salve for the wounds inflicted on our very soul by the commission of our sins. Our wounds thus healed in the forgiving grace of Jesus Christ our Lord, we receive his body and blood at the Lord’s table, the food and drink for the sustenance of our spirit. It is in Him alone we find salvation, and through him alone we find healing. Yet, we must come to him constantly for the healing of our wounds, lest the wounds remain and fester, and inflict us further in our sin. We must come to the Church, for it is indeed where we find Christ.
 - Romans 5:21
 - St. Symeon the New Theologian - Discourse 78
 - Saint Isaac of Syria - Mystic Treatises