An Ethiopian cannot change the color of his skin, nor can a leopard change his spots, yet many of the unrighteous have endeavored to change who they are through their efforts of self righteousness.
The Apostle Paul spoke of Israel as having a zeal for God yet attempting to establish their own righteousness apart from God by observance of the Law (Romans 10:2-3). Regrettably we admit that things haven’t changed much since the days of Paul. The unregenerate man trusts in his righteous works for salvation. Believers execute a relentless effort of self righteousness in hope of acquiring a sanctification that receives man’s applause and the approval of God.
A friend of mine has well stated that “we have learned Christianity in such a way that it has been useful for getting us to Heaven but very impractical for living life.” It might very well be advantageous for us to understand that righteousness can only be born at the death of self effort. Whether our self righteousness is employed in hopes of attaining eternal salvation or an attempt to secure our sanctification, it is all consummated as filthy rags,(Isaiah 64:6).
So the question remains, how shall the unrighteous be made righteous? It would be beneficial to note first that Old Testament believers who lived under the Law did not receive righteousness in the same manner as New Testament saints. In the Old Testament system believers received what we would term “imputed righteousness”. The word impute means to reckon or account. Abraham was a man of faith who believed God and it was accounted (reckoned, imputed) to him for righteousness (Gal 3:6) Faith is not a meritorious work; however faith was the vehicle through which righteousness was received. To impute or reckon means to take something that belongs to one person and credits it to the account of someone else. This is well illustrated in Romans chapter four. At best all that the Old Testament believers could possibly hope for was that righteousness would be credited to their account, but it was never a part of their being. On the contrary, New Testament saints do not receive righteousness rather they have been made righteous. It has been written into the very fiber of their being (Romans 5:19, II Corinthians 5:21).
It is a very real part of their identity. They need not strive for a certain desired behavior in order to become righteous or to attain righteousness. They are a new creation in Christ; therefore they are to live out of what they already possess. (II Corinthians 5:17) They are a new creation that has been created in true righteousness (Ephesians 4:24). The New Testament believer is righteous as a benefit of being in Christ who is righteous (I Corinthians 1:30). We are in Christ and Christ is in us (I Colossians 1:27), therefore Christ is our life (Colossians 3:4). We are never admonished to be imitators of His life but partakers of His life. When we receive His life we receive all that is true of Him, therefore as He is so are we (I John 4:17). In Adam we were all born sinners, but in Christ we are all made righteous, (Romans 5:19).
For Christ is the end of the law for righteousness to everyone who believes - Romans 10:4