Satan and the Demons
διάβολος — diabolos · dee-AH-voh-los
In brief
Satan is not God's opposite, and evil is not a rival power. The devil is a creature — an angel who fell by his own free choice — and the demons are angels who fell with him. Evil itself has no substance: it is a privation, a corruption of good things, the way rust is a corruption of iron. Orthodox spiritual life takes the demons seriously and fears them not at all, because Christ has already broken their power.
A creature, fallen
Scripture's names for the enemy describe his work, not a divine rank: the Hebrew satan means "adversary," the accuser; the Greek diabolos, "slanderer." He is one of the bodiless powers — created good, like everything God made, and fallen by his own free and unforced choice, in a rebellion the tradition places before the fall of man. The tradition has long read the taunt of Isaiah 14 — "How art thou fallen from heaven, O Lucifer, son of the morning!" — as a figure of that ancient fall, and Revelation pictures its end: "there was war in heaven," and the dragon was cast out with his angels (Revelation 12:7-9). Those angels are the demons. Christ speaks of the whole matter with terse authority: "I beheld Satan as lightning fall from heaven" (Luke 10:18), and calls him "a murderer from the beginning" and "a liar, and the father of it" (John 8:44).
Two things follow, and Orthodoxy insists on both. First, there is no dualism: Satan is not the dark half of the universe or God's equal opponent — if he is to be paired with anyone it is with his fellow creature the Archangel Michael, not with the Creator. Second, his power is parasitic and bounded. In the book of Job he must ask leave before he can touch anything, and receives limits with the permission. The devil is a defeated rebel on a chain — dangerous the way a cornered animal is dangerous, but never sovereign.
Evil has no substance
If God made everything, and everything He made is good, where did evil come from? The Fathers' answer is that evil never "came from" anywhere, because evil is not a thing. St. Basil the Great states it exactly: "Evil is not a living animated essence; it is the condition of the soul opposed to virtue, developed in the careless on account of their falling away from good." Evil is to good what darkness is to light and blindness to sight — not a second substance but a privation, a good thing bent or a good thing missing. No one has ever manufactured darkness; one can only block the light. Even the demons are not evil by nature — their created nature remains God's good work — but by will, frozen in refusal. This is the Church's deepest answer to the problem of evil: God made no evil thing, and creation has no dark twin.
Because his being is parasitic, the devil's whole method is deceit. The Wisdom of Solomon says that "through envy of the devil came death into the world" (Wisdom of Solomon 2:24) — envy, the misery of a creature that cannot create and can only spoil. He compelled nothing in Eden and has compelled nothing since: he can only suggest, accuse, and lie. The ascetic tradition maps his approach in the grammar of logismoi — the thought proposed, entertained, consented to — because the fall, first and every time after, happens by consent and never by conquest.
Warfare without fear
The Gospel is the account of the strong man bound: Christ withstands the tempter in the desert, casts out demons with a word, and on the Cross and in the harrowing of Hades breaks the tyranny of death by which the devil held the race. The Church has such confidence in this victory that she begins the making of every Christian with it: the traditional rite of baptism opens with exorcisms, and the candidate — or the godparent, for an infant — turns to the west, renounces Satan and all his works, and (in many uses) spits on him. Contempt, not terror, is the Church's liturgical posture toward the enemy.
The same sobriety governs daily life. Two opposite mistakes hand the demons more than their due: obsession, which sees a devil under every stone and forgets Christ's victory, and dismissal, which forgets there is a war on at all. The tradition walks between: spiritual warfare is real — "we wrestle not against flesh and blood, but against principalities, against powers" (Ephesians 6:12) — but its weapons are unglamorous: prayer, fasting, the sign of the Cross, the Holy Mysteries, watchfulness, and above all humility, which gives the accuser nothing to grip. St. Anthony the Great, whom the demons assaulted for decades in the Egyptian desert, left the Church its standing orders: "So then we ought to fear God only, and despise the demons, and be in no fear of them." The devil's noise is large and his leash is short: "Resist the devil, and he will flee from you" (James 4:7).