There are four possible relations between religion and morality, God and goodness.
Religion and morality may be thought to be independent. Kierkegaard’s sharp contrast between “the ethical” and “the religious,” especially in Fear and Trembling, may lead to such a supposition. But (a) an amoral God, indifferent to morality, would not be a wholly good God, for one of the primary meanings of “good” involves the “moral”—just, loving, wise, righteous, holy, kind. And (b) such a morality, not having any connection with God, the Absolute Being, would not have absolute reality behind it.
God may be thought of as the inventor of morality, as he is the inventor of birds. The moral law is often thought of as simply a product of God’s choice. This is the Divine Command Theory: a thing is good only because God commands it and evil because he forbids it. If that is all, however, we have a serious problem: God and his morality are arbitrary and based on mere power. If God commanded us to kill innocent people, that would become good, since good here means “whatever God commands.” The Divine Command Theory reduces morality to power. Socrates refuted the Divine Command Theory pretty conclusively in Plato’s Euthyphro. He asked Euthyphro, “Is a thing pious because the gods will it, or do the gods will it because it is pious?” He refuted the first alternative, and thought he was left with the second as the only alternative.
But the idea that God commands a thing because it is good is also unacceptable, because it makes God conform to a law higher than himself, a law that overarches God and humanity alike. The God of the Bible is no more separated from moral goodness by being under it than he is by being over it. He no more obeys a higher law that binds him, than he creates the law as an artifact that could change and could well have been different, like a planet.
The only rationally acceptable answer to the question of the relation between God and morality is the biblical one: morality is based on God’s eternal nature. That is why morality is essentially unchangeable. “I am the Lord your God; sanctify yourselves therefore, and be holy, for I am holy” (Lev. 11:44). Our obligation to be just, kind, honest, loving and righteous “goes all the way up” to ultimate reality, to the eternal nature of God, to what God is. That is why morality has absolute and unchangeable binding force on our conscience.
The only other possible sources of moral obligation are:
a. My ideals, purposes, aspirations, and desires, something created by my mind or will, like the rules of baseball. This utterly fails to account for why it is always wrong to disobey or change the rules.
b. My moral will itself. Some read Kant this way: I impose morality on myself. But how can the one bound and the one who binds be the same? If the locksmith locks himself in a room, he is not really locked in, for he can also unlock himself.
c. Another human being may be thought to be the one who imposes morality on me—my parents, for example. But this fails to account for its binding character. If your father commands you to deal drugs, your moral obligation is to disobey him. No human being can have absolute authority over another.
d. “Society” is a popular answer to the question of the origin of morality “this or that specific person” is a very unpopular answer. Yet the two are the same. “Society” only means more individuals. What right do they have to legislate morality to me? Quantity cannot yield quality; adding numbers cannot change the rules of a relative game to the rightful absolute demands of conscience.
e. The universe, evolution, natural selection and survival all fare even worse as explanations for morality. You cannot get more out of less. The principle of causality is violated here. How could the primordial slime pools gurgle up the Sermon on the Mount?
Atheists often claim that Christians make a category mistake in using God to explain nature; they say it is like the Greeks using Zeus to explain lightning. In fact, lightning should be explained on its own level, as a material, natural, scientific phenomenon. The same with morality. Why bring in God?
Because morality is more like Zeus than like lightning. Morality exists only on the level of persons, spirits, souls, minds, wills—not mere molecules. You can make correlations between moral obligations and persons (e.g., persons should love other persons), but you cannot make any correlations between morality and molecules. No one has even tried to explain the difference between good and evil in terms, for example, of the difference between heavy and light atoms.
So it is really the atheist who makes the same category mistake as the ancient pagan who explained lightning by the will of Zeus. The atheist uses a merely material thing to explain a spiritual thing. That is a far sillier version of the category mistake than the one the ancients made; for it is possible that the greater (Zeus, spirit) caused the lesser (lightning) and explains it; but it is not possible that the lesser (molecules) adequately caused and explains the greater (morality). A good will might create molecules, but how could molecules create a good will? How can electricity obligate me? Only a good will can demand a good will; only Love can demand love.
(Twenty Arguments for the Existence of God)