The Fall
God told Adam not to eat of the fruit, for in the day he eats of it he will surely die - literally, “dying you shall die” (Gen 2:16). God describes this consequence to Adam after his sin as physical death - you will return to the ground, for dust you are and to dust you shall return (Gen 3:146). Adam has fallen short of God’s glory and God cast’s him out of His presence, out from the Garden, lest he eat of the tree of life and live forever (Gen 3:23). Adam’s sin had two consequences. First there was the wages of sin, the death that is produced by sin, which Adam could not of himself escape as he was enslaved. Second there was the judgment of God. Adam was no longer fitted to be in the presence of God and was cast out. He fell short of the glory of God.
God also proclaimed a gospel in cursing the Serpent. Satan would crush the heel of the Seed of the woman and the Seed would crush Satan’s head (Gen 3:15). This, I believe, is a prophesy of a time when Jesus would be put to death by Satan in the body, but be made alive in the spirit (1 Peter 3:18).
The Problem
The problem of man is twofold: man sins, and man falls short of the glory of God (Rom 3:23). Sin produces death (James 1:15). Death carries with it a sting. It is appointed to man once to die and then the Judgment (Heb 9:27). There is none who are righteous (Rom 3:10-12; Psalm 14:1-3, 53:1-3) and all have sinned (Rom 3:23). Flesh and blood cannot enter the kingdom of God (1 Cor 15:50). That which is born of flesh is flesh (John 3:6).
Man was in bondage to Satan, under the bondage of sin and death. But because of sin we man was also the objects of God’s wrath and would perish when God judged the world.
The Solution
Two things had to be addressed because man’s problem had two very distinct aspects. Man’s enslavement to Satan, to the one who holds the power of death, to sin and death itself, had to be addressed. Also, man’s unrighteousness because of sins had to be addressed. These had to be addressed in a way that does not violate God’s own righteousness (God will not justify the wicked and God will not condemn the righteous, God will not punish the just, and God is a God who forgives sins).
We are born into this world in the image of Adam, who was made flesh and blood. The solution is more substantial than the payment of a debt. The solution is making man anew, making a new or Second Adam.
Our sins were laid on Christ, He bore our sins, as a substitute (representing the whole human race). Since we were flesh He too shared our humanity so that by His death He might break the power of him that holds the power of death – that is, the devil. He suffered the wages of sin, the consequences that sin produces. Christ suffered under the power of Satan because of our sin, however death could not hold Jesus. Jesus suffered what is appointed to man, death and then the judgment. He was raised on the third day.
Christ suffered for sins once for all time, the just for the unjust, so that He might bring us to God, having been put to death in the flesh, but made alive in the spirit (1 Pet 3:18). Where the first man (Adam) was made a living soul, the last Adam (Jesus) was made a life giving Spirit (1 Cor 15:45).
This solution addresses the twofold problem.
Christ was put to death in the flesh (1 Pet 3:18). He suffered under the power of Satan and broke the bondage that man suffered under. He suffered for our sins, but He is eternally righteous. Satan no longer had hold over man.
Christ was made alive in the spirit (1 Pet 3:18) and was made a life giving Spirit (1Cor 15:45). Although we die, yet shall we live (John 11:25). And this is a newness of life (Rom 6:4), it is being made a new creation in Christ (2 Cor 5:17), it is dying to sin and being made alive in Christ (Rom 6), it is doing away with the “old self” and putting on the “new self” which in the likeness of God has been created in righteousness and holiness of truth (Eph 4:23-24).
We are forgiven based on the blood of Christ which cleanses from all unrighteousness by making us new creations in Him, in Whom there is no condemnation.
Justice
When we are saved, are “in Christ” and “Christ in us” we are justified by declaration. We still struggle with sin, however Christ is the surety or guarantor of a better covenant. God can look at Christ as the guarantee of what we will be. He has predestined us to be conformed into the image of His Son, to be justified, and to be glorified. We will be refined, and if saved we are now in the process of being refined. But at Judgment there will be no wickedness found in us. No part of the “old self” which is guilty of sin will stand before God at judgment.
This view takes sin more seriously than a debt that must be paid. The wicked will perish. The wickedness in us has to perish, has to suffer the consequences of sins. Christ bore our sins bodily, and we must bear our sins bodily and die to the flesh.
God is just. God will never punish the righteous in order to clear the guilty (Prov 17:15). God will never punish the righteous (Prov 17:26). To do so would make God unjust. But God will recreate man, completely destroy the “old self” in us and make us new creations in Christ.
Rather than God punishing Jesus to pay our sin debt, Christ's blood cleanses us of all unrighteousness.
Conclusion
We see the salvation of the world in Christ’s death on the cross, because in His suffering and death Jesus freely took upon Himself the penalty of the sin of every human being that has ever walked the face of the Earth. He took upon Himself our bondage that we might be freed from those bonds. He took upon Himself our oppression that we might share in His victory over evil. He took upon Himself the consequences of our unrighteousness that we might be given freely the gift of His righteousness. He took upon Himself our condemnation that we might be granted His justification. He took upon Himself our death, that we might receive His eternal life.