As we come to the New Testament the idea of faithfulness is still what God expects. None of us go out and strive to build an ark simply because God does not require such today. We do not make yearly trips to Jerusalem in order to worship God because such is not required. What this does show us however, is that righteousness in this the Christian age is determined by what God has revealed. This has always been true in every generation of man upon earth. It is God, the lawgiver, who decides what is righteous, not man.
Man observes someone living a good moral life and reaches the conclusion that such a person could not ever be lost. Perhaps it is someone who by good deeds or their use of money blesses humanity. If man decides then the measuring stick would be how much good a person does. We pause to add here, that God is the lawgiver and not man. It is the expectations of God man should be concerned about. Paul writes that all men have sinned and come short of the glory of God (Rom. 3:23). Sin is the transgression of the law (I John 3:4). Man is not therefore born in sin but rather becomes a sinner. What God has said, is what makes a man a sinner or a righteous man.
At times some men misuse the scripture to be able to do what they want. A passage that has often been so used is John 1:17. There we are told that the law came by Moses. They use such a statement to reach the conclusion that we are not under law today. The verse finishes by telling us that grace and truth came by Jesus the Christ. Good students of the Bible want to know, “What is God’s will for us today?” What then is meant by grace and truth coming through Jesus? It cannot mean the removal of law, because how else would God determine that a man is righteous or not? We find then the expressions like, “the law of the Spirit”; “the law of Christ”; and the “perfect law of liberty” (Rom.8:2; Gal. 6:2; James 1:25).
Under the law of Moses, sin reigned unto death (Rom. 5:21). It was a good law that made the impression on the world around Israel that Israel was a good and wise people. Yet, this good law that revealed the nature of God to Israel could not solve the sin problem. It could not take away sin (Heb. 10:1-4). The remitting of sin required blood (Heb. 9:22). The blood of animals could not remove sin. It required the blood of Jesus the Christ, the Son of God (Eph. 1:7;Acts 20:28). Sin therefore reigned inasmuch as sin could not be removed by the actions of any man.
What does the rest of Romans 5:21 speak about? Sin reigned unto death but grace reigns through righteousness. The law came by Moses but grace and truth came by Jesus. Grace reigns through righteousness. Righteousness is defined by God and not by man. Let us go to the house of Cornelius and his meeting with Peter. Peter speaks about those whom God accepts? Who are they? The people who fear God and work righteousness (Acts 10:35). Oh, I thought righteousness was something God declared a person to be? Such is indeed the case because God is the lawgiver. What is true, however, in that definition is righteousness is determined by what a person does.
How can you know what you are supposed to do? One must come to the law of Christ to find out what it takes to please God (I John 3:22). If the Christian does not expend spiritual energy in the study of God’s Word, he cannot know what it takes to please God. Those who teach grace minus law do not understand how grace reigns. Grace reigns through righteousness. Righteousness determined by God the lawgiver.