Ask a juridical theology what sin is and the answer will be framed by penalty: what is owed, who pays, on what ground the debt is remitted. Ask Orthodox theology and the frame is medical. Sin is a sickness, the human being is a patient, Christ is the physician and the Church is a hospital. The two models are not gentle and harsh versions of one account; they ask different questions and get different answers, and much of what looks like Orthodox reticence about Western doctrines of atonement is simply the second frame declining the first frame's question.
The disease has a name in this literature. It is the passions, the pathe, and the word means both a passion and an affliction, something suffered as much as something done. A passion in this sense is not an emotion but a settled disposition in which desire, anger or thought has gone out of its proper order and now runs the person rather than being lived by them. The ascetic writings gathered in the Philokalia are clinical literature about exactly this: how each condition presents, what it is likely to do next, what treats it, and in what order.
The therapy is correspondingly practical. Watchfulness over the movements of one's own mind, continual prayer, fasting, obedience and the repetition of a short invocation are the standing prescriptions, and the spiritual father is the physician who applies them to a particular case rather than a judge who sentences it.
Confession sits inside this. The penitent stands before an icon of Christ, and the priest is present as witness and as physician; where a penance is given it is understood as medicine proportioned to the illness, not as punishment proportioned to the offence. And the end of the treatment is not acquittal but theosis, the participation of the human being in the life of God, which the fathers put as the claim that God became human so that the human might become divine.