Therefore, has that which is good become death to me? May it never come to be! But the sin [nature], in order that it is manifested sin, while working out death through the good to me, in order that the sin [nature] should become according to exceedingly sinful through the commandment (Romans 7:13).
We need to see the law for its purpose. It was not given to Israel as a means to demonstrate and maintain their own righteousness. When God brought them to Mount Sinai and instructed them to guard His covenant—the covenant of promise—Israel rejected it and sought to display their own righteousness. Then all the people answered together and said, “All which Jehovah has said, we will continually do” (Exodus 19:8). This sounds like a good response until we realize that in Hebrew, “do” is an incomplete action—an action that continues. God did not instruct them to do His word, but to guard His commandment. Their response should have been along the lines of a willingness to guard, not to continually do. Thus, the law was given to show that within us lies a sin nature that is exceedingly sinful and that, through our own self-effort, we cannot be righteous before God.
The grace believer is no different: he cannot live out the righteousness he has in Christ through law, for the law gives the sin nature strength. However, since Christ’s death and resurrection have been imputed to him, he is free from the dominion of the sin nature, enabling him to yield his members to righteousness—not through law, for that gives the sin nature strength, but through faith. Therefore, he acts in a righteous manner because he is righteous in Christ, and God has given to him all things pertaining to life and godliness.