Academic

The New Testament addresses the believer with genuine commands. Paul charges the church to “put to death the deeds of the body” (Rom. 8:13, English Standard Version) and to walk in “newness of life” (Rom. 6:4), and he directs these charges to those whom God has already justified freely by His grace. This combination creates a durable theological problem: if a sinner is justified through faith alone, apart from any work, what is the believer doing when he obeys these imperatives, and what relation does that obedience bear to the faith by which he was justified?

The gospel announces that God has saved sinners through the death of His Son. What it does not immediately explain is why this death, of this Person, accomplishes what no other death could. Why did the author of Hebrews insist that the blood of bulls and goats could never take away sins, and that the blood of Christ does? The answer Scripture gives is bound up with who the One who died actually was. Because atonement requires both infinite satisfaction and genuine human substitution, Christ's atoning work is efficacious only because the one person who offers it is both God and man.