by John Calvin
For [Christ] himself is our peace, who has made the two one and has destroyed the barrier, the dividing wall of hostility, by abolishing in his flesh the law with its commandments and regulations. His purpose was to create in himself one new man out of the two, thus making peace, and in this one body to reconcile both of them to God through the cross, by which he put to death their hostility.
God, in order to remove any obstacle to his love towards us, appointed the method of reconciliation in Christ. There is great force in this word propitiation; for in a manner which cannot be expressed, God, at the very time when he loved us, was hostile to us until reconciled in Christ... The nature of this mystery is to be learned from the first chapter to the Ephesians, where Paul, teaching that we were chosen in Christ, at the same time adds, that we obtained grace in him. How did God begin to embrace with his favour those whom he had loved before the foundation of the world, unless in displaying his love when he was reconciled by the blood of Christ?
- John Calvin (1509-1564), The Institutes of the Christian Religion, v. I 
The second requirement of our reconciliation with God was this: that man, who by his disobedience had become lost, should by way of remedy counter it with obedience, satisfy God’s judgment, and pay the penalties for sin. Accordingly, our Lord came forth as true man and took the person and the name of Adam in order to take Adam’s place in obeying the Father, to present our flesh as the price of satisfaction to God’s righteous judgment, and, in the same flesh, to pay the penalty that we had deserved. (Institutes, II.xvi.3)
But that these things may take root firmly and deeply in our hearts, let us keep sacrifice and cleansing constantly in mind. For we could not believe with assurance that Christ is our redemption, ransom, and propitiation unless he had been a sacrificial victim. Blood is accordingly mentioned wherever Scripture discusses the mode of redemption. Yet Christ’s shed blood served, not only as a satisfaction, but also as a laver [cf. Eph. 5:26; Titus 3:5; Rev. 1:5] to wash away our corruption. (Inst., II.xvi.6)