The Westminster Shorter Catechism, summarizing the biblical teaching on the topic, says that all mankind sinned in Adam, “and fell with him in that first transgression.” Because Adam was in a covenant situation, our representative, his trespass led to our condemnation (Rom. 5:18). How does this work? How come I bear the guilt for Adam’s sin? J. Gresham Machen explained this very well in The Christian View of Man. Note how he ties it in with the gospel:
…I should just like to point out to you that if it is impossible in the nature of things for one person to bear the guilt of another person’s sins, then we have none of us the slightest hope of being saved and the gospel is all a delusion and a snare. At the heart of the gospel is the teaching of the Bible to the effect that Jesus Christ, quite without sin himself, bore the guilt of our sins upon the cross. If that be true, then we cannot pronounce it impossible that one person should bear the guilt of another person’s sins.
The Apostle Paul insists upon this analogy in the latter part of the fifth chapter of Romans. In that part of that chapter we find set forth the great Scripture doctrine that is called the doctrine of imputation.
That doctrine, if you take it as the Bible sets it forth as a whole, involves three great acts of imputation. First, Adam’s first sin is imputed to his descendents. Second, the sins of saved people are imputed to Christ. Third, Christ’s righteousness is imputed to saved people.
When the Bible teaches that the sins of saved people are imputed to Christ, that means that Christ on the cross bore the penalty rightly resting on saved people. He was not deserving of death; he had not sinned at all. Yet he suffered as though he had sinned. God treated him as though he had sinned, although he was not a sinner. The sin for which he died was not a sin that he had committed; it was our sin that was imputed to him.
So when the Bible teaches that Christ’s righteousness is imputed to saved people, that does not mean that the saved people are then actually righteous. On the contrary, they are sinners. But they receive the blessed reward of life which Christ’s righteousness deserved. Christ’s righteousness is not actually theirs, but it is imputed to them.
So that’s what we mean when we talk about being justified by faith alone!
Covenant Presbyterian Church (OPC)
Hammond, WI, 54015