There are many reasons we know the Moral Law exists, and we will present and discuss eight of them.
- The Moral Law Is Undeniable Like absolute truth, absolute values are also undeniable. While the claim “There are no absolute values” is not self-defeating, the existence of absolute values is practically undeniable. For the person who denies all values, values his right to deny them. Further, he wants everyone to value him as a person, even while he denies that there are values for all persons. Those who deny all values nevertheless value their right to make that denial. And therein lies the inconsistency. Moral values are practically undeniable.
- Our Reactions Help Us Discover the Moral Law (Right from Wrong) Moral Law is not always apparent from our actions, as evidenced by the terrible things human beings do to one another. But it is brightly revealed in our reactions—what we do when we personally are treated unfairly. In other words, the Moral Law is not always the standard by which we treat others, but it is nearly always the standard by which we expect others to treat us. It does not describe how we actually behave, but rather it prescribes how we ought to behave. For example, I may not think stealing is wrong when I steal from you. But watch how morally outraged I get when you steal from me.
- Without the Moral Law, There Would Be No Human Rights Thomas Jefferson (3rd US President) wrote, in the Declaration of Independence: We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed (emphasis added). Notice the phrase, “they are endowed by their Creator with certain unalienable Rights.” In other words, America's Founding Fathers believed that human rights are God-given, and, as such, they are universal and absolute—they are the rights of all people, in all places, at all times, regardless of their nationality or religion. Jefferson and the other Founding Fathers recognized that there was a higher authority—the “Creator”—to whom they could appeal to establish objective moral grounds for their independence. For e.g. We can't say that the Nazis were absolutely wrong unless we knew what was absolutely right. But we do know they were absolutely wrong, so the Moral Law must exist.
- Without the Moral Law, We Couldn’t Know Justice or Injustice Perhaps the most popular argument against the existence of God is the presence and persistence of evil in the world. If there really is a good and just God, then why does he allow bad things to happen to good people? Atheists have long asserted that it would be more logical to believe that this God doesn’t exist than to try and explain how evil and God can coexist. C. S. Lewis was one such atheist. He believed that all of the injustice in the world confirmed his atheism. That is, until he thought about how he knew the world was unjust: He wrote, “[As an atheist] my argument against God was that the universe seemed so cruel and unjust. But how had I got this idea of just and unjust? A man does not call a line crooked unless he has some idea of a straight line. What was I comparing this universe with when I called it unjust?” This realization led Lewis out of atheism and ultimately to Christianity. For now, the main point is this: if there were no Moral Law, then we wouldn’t be able to detect evil or injustice of any kind. Without justice, injustice is meaningless. Likewise, unless there’s an unchanging standard of good, there is no such thing as objective evil. But since we all know that evil exists, then so does the Moral Law.
- Without the Moral Law, There Would Be No Way to Measure Moral Differences If the Moral Law doesn’t exist, then there’s no moral difference between the behaviour of Mother Teresa and that of Hitler. Likewise, statements like “Murder is evil,” “Racism is wrong,” or “You shouldn’t abuse children” have no objective meaning. They’re just someone’s opinion, on a par with “chocolate tastes better than vanilla.” But we know they do have meaning. For example, when we say “society is getting better” or “society is getting worse,” we are comparing society to some moral standard beyond ourselves. That standard is the Moral Law that’s written on our hearts. In short, to believe in moral relativism is to argue that there are no real moral differences between Mother Teresa and Hitler, freedom and slavery, equality and racism, care and abuse, love and hate, or life and murder. We all know that such conclusions are absurd. So moral relativism must be false. If moral relativism is false, then an objective Moral Law exists.
- Without the Moral Law, You Couldn’t Know What Was Right or Wrong Relativists are famous for this kind self-defeating arrogance. They claim there is no truth, but then make truth claims of their own. They claim they don’t know what is right, but then claim their own political causes are right. They deny the Moral Law in one sentence and then assume it in the next. Christians are often criticized for stating that they “have the truth,” but there's this atheist stating that he has the truth that no one has the truth. In order to know that no one has the truth, the atheist would have to know the truth himself.
- Without the Moral Law, There Are No Moral Grounds for Political or Social Dissent If there is no Moral Law, then no position on any moral issue is objectively right or wrong—including the positions taken by atheists. There would be nothing wrong with racism, or imperialistic wars. Nor would there be anything wrong with prohibiting abortion. In fact, without the Moral Law, no one has any objective grounds for being for or against anything! But since we all know that issues involving life and liberty are more than mere preferences—that they involve real moral rights—then the Moral Law exists.
- If There Were No Moral Law, Then We Wouldn’t Make Excuses for Violating It Did you ever notice that people make excuses for immoral behaviour? Making excuses is a tacit admission that the Moral Law exists. Why make excuses if no behaviour is actually immoral? We only make excuses when we act against the Moral Law. We wouldn’t do so if it didn’t exist.