2 Cor 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made th righteousness of God in him.
Adam’s sin in the Garden separated him from God and made him unrighteous in God’s sight. Through his disobedience, spiritual death passed upon all men in the human race and many were made sinners. To be declared righteous we would have to be acquitted or declared not guilty of our sin. To be righteous is to be morally blameless, innocent, and measuring up to God’s standard of moral perfection.
God communicated to man his need of righteousness by giving the Law through Moses. The law of Moses spelled out what was holy, just and good (Rom. 7:12) and how far man had fallen from God’s standard of moral perfection. The Law would:
DEFINE SIN or bring the knowledge of sin.
IMPUTE GUILT to all or declare the whole world guilty before God.
POINT TO THE SAVIOR or their need of a Savior.
The problem was that only the doers of the Law could be justified or declared righteous before God (Rom. 2:13) but man in his fallen state could never measure up to God’s standard of righteousness and moral perfection. Our solution was for God to send Jesus as our substitute to perfectly keep the Law and take the punishment (die) for our sin. Because the punishment for our sin was placed on Jesus as our Substitute on the Cross, the guilty verdict is removed and we are declared righteous (Rom. 3:24, 28; 5:1,9). He took our sin and gave us His righteousness. Another way to say it is that by putting our faith in Jesus (His DYING for our sin and DOING of the law), Christ is the end of our conduct to get righteousness. It is righteousness by faith not by works.
Righteousness is all that God requires man to be that he couldn’t be in himself (without his own deeds of keeping the Law (Rom. 3:21-23), given as a free gift (Rom. 5:17). When we accept Jesus as Lord and Savior by faith, we enter into a state of being right, just, innocent, morally blameless, and holy according to God’s own perfect standard of what is right. God’s righteous nature (Eph. 4:24) becomes ours when we accept Jesus (Rom. 3:21 26). Now that we are righteous as Christians, it will affect our conduct. Our being righteous inwardly makes possible a holy life outwardly. We can do right because we’ve been made right.