"For if, when we were God’s enemies, we were reconciled to Him through the death of His Son, how much more, having been reconciled, shall we be saved through His life!" (Romans 5:10).
“Bumper sticker theology” says “Smile, God loves you.” This kind of slogan communicates to people that God will save them because He is nice and forgiving. He is willing to overlook our sin because He is generous. Though many well-meaning Christians think this way, such an indiscriminate view of God’s salvation is implicitly pagan and radically contradicts the perspective of Biblical Christianity.
God is holy and cannot overlook sin. In order to overlook injustice, He would have to sacrifice the perfect justice of His own moral character. Thus, as Exodus 23:7 and 34:7 both say, God will by no means ever clear the guilty. He will never let a guilty person go free and unpunished.
Think about it: If God were mushy and changeable, and willing simply to dismiss sin, how much confidence could we have in Him? He certainly would no longer be the Rock that never changes, in whom we can repose in total confidence.
Since God will not simply overlook sin, how can we be saved? If God will never clear the guilty, and we are guilty, how can we be delivered? The answer can only be that God removes our guilt so that we are no longer guilty and therefore no longer condemned.
God’s design to remove our guilt was accomplished by the twofold work of Christ involving what we call His passive and His active obedience. Jesus’ passive obedience was His willingness to die for our sins while His active obedience was His fulfillment of the law. Sins were put upon Him, and He died for them. His righteousness is put upon us, and we live for that reason. This transfer of sin and righteousness is called imputation. Our sins and sin nature were imputed to Jesus, and His righteousness is imputed to us.
Both aspects of imputation are necessary for our salvation. Transference of our sin to Jesus can make us innocent, but it cannot make us just or righteous. It is righteousness, not innocence, that gets us into the kingdom of God (Matthew 5:20). Not only is our sin transferred (imputed) to Christ, but His righteousness is imputed to us, transferred to our credit so that in God’s sight we are righteous.
In the United States, there is a great misunderstanding in this vital area of justification, salvation and the lordship of Christ. If you have not yet done so, consider reading Dr. John MacArthur's The Gospel According to Jesus or RC Sproul's Getting the Gospel Right.