If there is only one, true creator God, then only the law of our Creator can serve as the fixed, transcendent basis for human ethics. We find our Creator’s law in Scripture, particularly in the Mosaic law, which includes ceremonial and civil regulations designed for ancient Israel as well as moral commandments that apply in every time and place. In particular, as Christians from nearly every theological tradition have understood, the Ten Commandments express these unchanging moral requirements.
Christian theologians have also noted that one does not have to have access to a Bible in order to know these transcendent moral standards. Having the commandments inscripturated in texts such as Exodus 20 and Deuteronomy 5 is a great benefit, for God’s special revelation clarifies His requirements for sinners whose hearts have been dulled to His standards. Nevertheless, one does not need the Bible to have a basic understanding of God’s law. There is such a thing as natural law, law that the Lord has given to all people in creation. Even the Gentiles—those outside of God’s covenant with Moses and who therefore lack Scripture—sometimes do what God’s law requires, albeit imperfectly, outwardly, and superficially (Rom. 2:14). Our Creator has inscribed His basic demands on the consciences of the creatures He has made in His image (Gen. 1:26–27). Even the stoniest of human hearts has awareness of these commandments, meaning that sinners cannot say on judgment day that they did not know what God wanted from them.
Scripture testifies to the existence of God’s law in nature, but we also find evidence of it in various human law codes. Legal systems vary in many ways from culture to culture, but there are certain laws that we find in every society. All cultures, for example, prohibit the taking of innocent life. Fallen people have in many ways twisted and suppressed God’s original law against murder (Gen. 9:5–6), but one would be hard-pressed to find a culture that says murder is ethically permissible.
Deny natural law and the only possible end is moral relativism. Thus, the ascendancy of moral relativism in the United States and other Western countries has attended the widespread denial of natural law. Recovering natural law would go a long way toward steering the West out of the dead end of moral relativism.