There are many theories about how Jesus' death on the Cross makes reparation for the sins of all mankind.
God is not under any law.
Why do the Scriptures portray the death of Jesus as something required by law? What kind of "reconciliation" can God ever need? Isn't is just sufficient for God to say, "You are forgiven." Why did God the Son have to come in Person and die for our sins? Why do we have to suffer and die?
- Cath Encyc
- Conquest, captivity, and ransom are familiar facts of human history. Man, having yielded to the temptations of Satan, was like to one overcome in battle. Sin, again, is fitly likened to a state of slavery. And when man was set free by the shedding of Christ's precious Blood, this deliverance would naturally recall (even if it had not been so described in Scripture) the redemption of a captive by the payment of a ransom.
- But however useful and illuminating in their proper place, figures of this kind are perilous in the hands of those who press them too far, and forget that they are figures. This is what happened here. When a captive is ransomed the price is naturally paid to the conqueror by whom he is held in bondage. Hence, if this figure were taken and interpreted literally in all its details, it would seem that the price of man's ransom must be paid to Satan. The notion is certainly startling, if not revolting. Even if brave reasons pointed in this direction, we might well shrink from drawing the conclusion. And this is in fact so far from being the case that it seems hard to find any rational explanation of such a payment, or any right on which it could be founded.
- Anselm's answer to the question is simply the need of satisfaction of sin. No sin, as he views the matter, can be forgiven without satisfaction. A debt to Divine justice has been incurred; and that debt must needs be paid. But man could not make this satisfaction for himself; the debt is something far greater than he can pay; and, moreover, all the service that he can offer to God is already due on other titles. The suggestion that some innocent man, or angel, might possibly pay the debt incurred by sinners is rejected, on the ground that in any case this would put the sinner under obligation to his deliverer, and he would thus become the servant of a mere creature. The only way in which the satisfaction could be made, and men could be set free from sin, was by the coming of a Redeemer who is both God and man. His death makes full satisfaction to the Divine Justice, for it is something greater than all the sins of all mankind.
"For God indeed was in Christ, reconciling the world to himself" (2 Corinthians 5:19).
"even as the Son of man is not come to be ministered unto, but to minister, and to give His life a redemption for many" (Matthew 20:28);
"Because in him, it hath well pleased the Father that all fulness should dwell; and through him to reconcile all things unto himself, making peace through the blood of his cross, both as to the things that are on earth, and the things that are in heaven." (Colossians 1:19-20).
"Forgive us our debts as we forgive our debtors."
"If you do not forgive others' trespasses, your trespasses will not be forgiven."
"For you are bought with a great price" (1 Corinthians 6:20).
"Thou art worthy, O Lord, to take the book, and to open the seals thereof; because thou wast slain, and hast redeemed to God, in thy blood" (Revelation 5:9). 
Nicene Creed, "who for us men and for our salvation, came down, took flesh, was made man; and suffered.
Jesus acts as the representative (Latin: vicar) of all sinners.
He also acts as God's vicar.
His death is of infinite worth because He is a Divine Person, eternally begotten of the Father from before all time.
His death is a human action because He has a full human nature and is truly human.
His death is a divine action because He participates fully in the Divine nature--He is homoousios, consubstantial, "one in being" with the Father and the Spirit--and is truly God.
The action of Jesus on the Cross is the action of the Father and the Spirit as well, although only the Son became human and only the Son suffered and died on the Cross. Jesus' Incarnation and atoning action are "by the will of the Father and the work of the Holy Spirit."
Professional sports are our great national example of vicarious satisfaction. The players on the field represent us. We're elevated by their victories and cast down by their defeats. We share with them vicariously. That's what is going on in the Eucharist and the lives of the saints. Communion of the saints. We're connected. We care. We bear each other up--or, as in the case of the priest scandals, we cast each other down.
God is involved in every sin
We "we live and move and have our being" in God (Acts 17:28).
It is not so much that God is in the universe as that the universe is in God.
All sin takes place in God, turning God's gifts against Him, against ourselves, and against others.
God is therefore involved in all of our sins directly and immediately. If He did not allow us to sin, we could not sin. If He did not allow us to use His power to hurt one another, we could not hurt one another.
Our sins are a misuse of the power that God the Creator gave us.
Our sins against love injure both our relationship with God and with our neighbor.
The sinner therefore incurs a debt to God as well as a debt to those sinned against. Those who are sinned against have a claim not only on the sinner but on God as well, for if God had not created a universe in which innocent people can suffer, they would not have suffered.
In His Incarnation and death, God the Son collects all debts and pays them all by enduring suffering and death freely and graciously. He did not have to do this, but He did. He atones for the whole history of sin by embracing the consequences of sin in Himself.
The Atonement not only settles sin between us but absolves God from allowing sinners to cause us to suffer.
All innocent suffering is rewarded.
Suffering and death are not greater than God.
They are overthrown by God's love.
Suffering and death are not the greatest evil.
Alienation from God, self, and others is the greatest evil. Hell is the state of ultimate separation from all others, insofar as the creature (angelic or human) is capable of deciding to reject love.
Suffering and death are passing realities.
They are swallowed up in glory by the Resurrection.
All of our tears will be turned into joy.
God's power to forgive sin is not arbitrary or extrinsic. If there is a God, there are no secular relationships. God is pure Spirit, which means that He is not bound by space or time. He is the author of all of the laws of nature, not their subject. Wherever two or three are gathered, there God is in their midst. Wherever one sins against another, God is offended. The sinner uses the power God provides to injure a person whom God loves with His whole heart. God is not butting into someone else's business when He commands the wrongdoer to repent and the victim of wrongdoing to forgive. The injury could not have happened except by God's permission; it cannot be healed without His participation.
There are no God-free relationships. Secularism is short-sighted.
Jesus' death on the Cross is God's reparation for allowing us to suffer.
He created the world in which there can be innocent suffering.
It is He who is responsible for all evildoing.
On the Cross, Jesus demonstrates that we can pass through suffering and death to life.
A word from a distance would be so cold by comparison.
Jesus' death on the Cross is God's word of mercy. His word of mercy is His Word. His word of mercy is real and active, it takes flesh and dwells among us.
Jesus is how God says, "I forgive you. I'm sorry for your suffering and death. In my only-begotten Son, you will be healed, restored, sanctified, and raised to new life."
As the mystic, Julian of Norwich, is said to said, "All will be well again, and all manner of thing will be well again, I know."
- We must give back what we have stolen.
- We must repair what we have broken.
- We must suffer what we have caused others to suffer.
Rounders: A career criminal bought up all of the debts of a poker player so that he could 'own' him. God buys up all of our debts to each other so that He can set us free. Everyone who has a claim on another must settle that claim through Jesus.
Punishments for sin
All of God's punishments are just.
No one is in Heaven by accident or against their will.
No one is in Hell by accident or against their will.
They are all intrinsic and perfectly suited to the wrongdoing. The punishment "fits the crime."
Love requires purification and amendment--for the sake of the forgiven sinner as well as for the sake of those injured by the sinner.
Jesus won the contest
Jesus was not crushed by His suffering.
He overcame it.
He endured it for the sake of the joy that was set before Him (Heb 12:2).
Suffering and death are not the greatest evils.
Sin is the greatest evil.
- Pulled out of a pit.
- Washed clean.
- Plugged into our power supply.
- Born again / born from above.
- Commissioned with the same Spirit.
- Deification: God became man so that man could become God (St. Athanasius, De Incarnatione Verbi, 54).
- "Looked at in this light, the Atonement appears as the deliverance from captivity by the payment of a ransom" (Catholic Encyclopedia, "Atonement."