God created human beings to enjoy sweet fellowship with himself. But instead of obeying God, we have broken his laws, ignored his wishes, displeased him and gone astray. As surely as human life is God’s gift, just that surely the consequence of sin is death (Rom. 6:23). How can a just and merciful God pronounce sinners “not guilty” and treat them as if they have done exactly what he desired? If he shows mercy, he will not be just. If he does justice, he will not show mercy. Humanly speaking, grace seems an impossible dream. God resolved this dilemma in the person of Jesus of Nazareth. God himself took on human nature and became a baby boy in the womb of the Virgin Mary.
In Jesus, the offended came to the offenders. In a human body, created for that purpose, Jesus gave God the perfect human obedience he had always wanted but had never before received (Heb. 10:5-10). By doing that, Jesus showed God’s law to be both great and glorious (Isaiah 42:21). In one of his last prayers, Jesus could say, “I have finished the work that you gave me to do” (John 17:4). Jesus then offered that faithful life “for sin,” in his body on the cross, fulfilling the Isaiah prophecy of one who would “make his life an offering for sin” (53:10).
On the cross like a great lightning rod suspended between heaven and earth, Jesus absorbed all the consequences of human sin — consequences culminating in his death. At the same time, Jesus gave God the Father the only life ever lived in perfect loving obedience to him. Jesus could therefore shout from the cross, “it is finished!” and with the satisfaction of an accomplished work, die satisfied (John 19:30; Isa. 53:11). God’s grace did not come cheap, although for its recipients it is absolutely free.
In the work that accomplished salvation, there is no such thing as “God’s part” and “our part.” It was wholly God’s work to reconcile, justify and redeem, and he did that in Jesus, once for all. Our work comes after God has finished his work, and it is totally a response to God’s work — of grateful obedience and praise. Not until we have accepted the “it is finished!” concerning Jesus’ work are we ready to hear “It is beginning” concerning our own work. And God’s saving work is what he did in Jesus, not something he does in us. It was outside of us, for us.