For even the Son of Man did not come to be served, but to serve, and to give His life a ransom for many. (Matthew 20:28, Mark 10:45)
“Ransom” language about the crucifixion emphasizes both our captivity to the devil and the great price Christ paid to set us free.
There is a right way and a very popular but wrong way to think of how He ransomed us. The wrong way is pointed out by St. Gregory Nazianzus:
To whom was that blood offered that was shed for us, and why was it shed? I mean the precious and glorious blood of God, the blood of the High Priest and of the Sacrifice. We were in bondage to the devil and sold under sin, having become corrupt through our concupiscence. Now, since a ransom is paid to him who holds us in his power, I ask to whom such a price was offered and why? If to the devil, it is outrageous! The robber receives the ransom, not only from God, but a ransom consisting of God himself. He demands so exorbitant a payment for his tyranny that it would have been right for him to have freed us altogether. But if the price is offered to the Father, I ask first of all, how? For it was not the Father who held us captive. Why then should be blood of His only begotten Son please the Father, who would not even receive Isaac when he was offered as a whole burnt offering by Abraham, but replaced the human sacrifice with a ram? Is it not evident that the Father accepts the sacrifice not because he demanded it or because He felt any need for it, but on account of economy: because man must be sanctified by the humanity of God, and God Himself must deliver us by overcoming the tyrant through His own power, and drawing us to Himself by the mediation of the Son who effects this all for the honor of God, to whom He was obedient in everything... What remains to be said shall be covered with a reverent silence… (In sanctum Pascha, or. XLV, 22’, P.G., t 36, 653 AB, quoted in Lossky, Mystical Theology, p. 153.)
The wrong way to understand Christ's having ransomed and redeemed us, then, is the overly literal way.
In Orthodox understanding, Christ “paid the price” for our redemption in much the same way a soldier might pay a heavy price, might even “pay the ultimate price”, his life, to free his country. Or when we look at the body of a victorious athlete, sweaty, dehydrated, exhausted, aching, when we consider how much of his life he had to give up for training, and when we say what a stiff price he paid for his victory, we do not mean he bribed the judges or referee or paid off his opponent. We mean he endured a severe ordeal. That is how we mean it when we speak of Christ having ransomed us or having bought us with a price.
We do not mean that God exacted any price, but that the circumstances did. We have seen some of those circumstances in previous posts in this series. One of them was that the Old Covenant remained unfulfilled; and if it was not to have existed all those millennia for nothing, it must be fulfilled, by a sacrifice of perfect obedience, before the New Covenant was instituted. Another circumstance was that the divine, immortality-bearing blood was needed for giving us life. Death must be defeated, satan must be deprived of his subjects, ultimate love and forgiveness must be openly revealed, and so forth. Such tasks, exacting a stiff "price," were left for Jesus to do if we were to be saved. God the Father did not require to be paid off in exchange for being merciful, though; such a notion leaves no room for forgiveness.
Truly, there are whole theologies (almost all heterodox theologies, in fact) that leave no room for actual forgiveness, in fact deny it, and can only offer us the shabby and gloomy alternative of displaced punishment. That is because there are people who think it would be morally wrong for God simply to forgive outright, without taking "just retribution", on the theory that to to so would undermine the moral foundations of the world. To fail to punish, to offer "bare amnesty" would be, they think, conniving in the evil.
But for the Orthodox, the foundation of the world is not a moral code, but a Person, Jesus Christ. And it is perfectly just for Him to do whatever He wants with what is His own. (Matthew 20:15) He is allowed to have mercy, true, free mercy, upon whom He will have mercy. (Exodus 33:19, Romans 9:15,18) He is not required to strike some legal bargain. The law is not the be-all and end-all, Alpha and Omega; Jesus Christ Himself is. (Revelation 1:8, 11; 21:6; 22:13) Nor does forgiving a sin equate to conniving in it. Much to the contrary, forgiveness, bare amnesty, is a major component of how God eradicates sin. Forgiveness is a principal weapon in the arsenal of arms against the devil. And as far as I know or can think, Orthodox Christianity is the only faith that genuinely offers it.
When we speak of Christ having ransomed us or redeemed us, then, we refer to our slavery to satan and how much He gave to liberate us from it. We mean that to get us back from sin and death cost Him a great deal - a price He gladly paid, for love of you and me, "who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God." (Hebrews 12:2)