There are three words that we can easily commit to memory, which outline the wonderful things that Jesus accomplished by dying on the cross. These are necessary things which we could not possibly have

Jesus offered to God
his perfect life for us
because we could not offer
a perfect life of our own.
We are all born perfect. because God created our inmost being
But we are born into an imperfect world, and we have all allowed our perfect selves to be spoiled by the world. "Through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned"
One man, however, made himself an exception. He said, "Be perfect as your heavenly Father is perfect"
Jesus was tempted in a special way by the devil in the wilderness
As he came to his death, he was sorely tempted still. "His sweat became like great drops of blood"
When we compare ourselves to Jesus, how imperfect we are! We cannot bring to God a perfect life. So we face rejection. Perhaps we could offer some substitute? Find another creature that is perfect, a lovely bird, an unblemished lamb? God did accept such offerings for a while, but he was never satisfied
We can find but one substitute: the perfect life of Christ. When he "offered himself without blemish to God"
This covering of our own imperfection by the perfection of Christ, is called "sanctification". Christ is our "justification, sanctification, and redemption"
Jesus was punished
instead of us
because our own punishment
would have to be everlasting.
God's severity
In theory, we could expiate our sins by suffering the just punishment for them. But in practice that is impossible, because the just punishment is nothing less that the everlasting punishment prepared and reserved for the devil and his angels
God gives every human being in the womb a perfect spirit destined for eternal life with God in glory. The punishment for spoiling that perfection is not merely that this destiny is delayed, or that its glory is lessened, but that it is utterly lost. Since the punishment is eternal, it excludes eternal life.
But there is a solution. We recall that when Jesus offered his perfect life to God, he suffered punishment, which the Holy Spirit calls "the agony of death"
There can be only one reasonable answer to the question just asked. He must have been punished for the sins of someone else, and punished in their stead. That is why the gospel says, "The chastening for our well being fell upon him"
This punishment of the just for the unjust, is marvelous: Jesus, being perfect, was able to be "freed from the agony of death"
This acceptance of Christ's punishment on the cross as a substitute for our own eternal punishment, is called "justification". Christ is our "justification, sanctification, and redemption"
Jesus paid the price
for us which we could not
give in exchange
for our own souls..
God demands even more than perfection and punishment. He also demands a price be paid. When we look at our ruined lives we can see that we no longer belong to God, we belong to Satan. We must say with Paul, "I am carnal, sold under sin"
Only those who belong to Satan face the eternal punishment prepared for Satan! Why should we share Satan's destiny if he does not own us? We became his possession when we sinned, and
God will not fight injustice with injustice. God will not steal from Satan what belongs to Satan, no matter how deceptively Satan engineered that ownership. We can be transferred from Satan's ownership to God's ownership only upon payment of
We sold ourselves for a price --the pleasures of sin for a season
Our only hope would be to find someone able to pay a price in exchange for our souls. That is not so hopeless as it sounds, because there is such a one. It is Jesus, and the price is his blood. Jesus does not have to give anything in exchange for his soul, because he is perfect. So when he gave his own precious blood, God deemed that a suitable price so to cancell Satan's claim upon us, if we wish.
Thus the severity of God falls upon Jesus, and the goodness of God falls upon us.
This paying of our purchase price, is called "redemption". He is our "justification, sanctification, and redemption"