The argument for God’s existence from objective moral values states that some things are really wrong in themselves, not because society says so or because some human choices may be inherently helpful in survival while others are harmful. Abuse, rape, and child torture are really wrong and not just socially unacceptable behaviors. Conversely, honesty, love, and self-sacrifice are values that have no biological explanation nor have they been proven to help humans survive. The argument from objective moral values to God’s existence runs like this:
1. If objective moral values exist, then God exists.
2. Objective moral values exist.
3. Therefore, God exists.
It is important to understand that it’s not necessary to believe in God in order to live moral lives. Many people who do not believe in God lead good lives that are virtuous and morally upright. What I’m saying is that for objective moral values to exist the best explanation is that there is a moral Lawgiver. Of course, if objective moral values do not exist, then the most anyone can claim as the basis for good behavior is reason, personal preferences, or agreed upon standards in society. For the atheist then, incest or rape may not be socially advantageous, but these acts cannot be objectively wrong, only relatively wrong. If a person can avoid the negative consequences of committing these acts, then there is nothing really wrong with them. since there is no objective moral standard against which to measure their goodness. Given enough time and change, society will alter its beliefs and moral values simply become moving targets within individuals or a people group.
As for objective moral values finding their source in reason, Immanuel Kant claimed that “all moral conceptions have their seat and origin completely a priori in the reason” (Fundamental Principles on the Metaphysics of Morals). But this must be rejected as false, because it confuses the abilities of human reason with the nature of reason. Simply because reason has the ability to discern objective moral values does not mean reason is the source of those objective moral values. Against Protagoras, “Man is [NOT] the measure of all things.” Were it not for humans being made after the image of their Creator, then even the ability to discern objectively right from wrong would be absent.
What about those who claim “I am the authority on who/what is my moral authority?” It is important to distinguish between recognition and attribution. I may be able to recognize a moral authority but this does not mean that moral authority is attributed to me. For example, if I assert that it is wrong to drive faster than the speed limit, I am not necessarily the authority on speeding. Rather, I am simply recognizing an authority (civil government) outside of myself. Likewise, to recognize that God is the ground of objective moral values is not to set one’s self up to be the authority in any ultimate sense, but merely to assert a starting point for objective moral authority.
The believer in God insists that certain acts are really wrong and they’re wrong because God defines what is right and what is wrong. But of course, this requires God’s existence. If God does not exist, then what is left over morally? Consider the penetrating words of E. J. Carnell who insists that without God:
humanity appears to be but a huddling mass of groveling protoplasm, crowded together in a nervous wait for death, not unlike a group of helpless children that aggregate together in a burning building, pledging to love each other till the end comes . . . we are all going to die, and . . . ‘the wages of virtue is dust.’
Edward John Carnell, An Introduction to Christian Apologetics (p. 327)
And so, given God’s existence, how does one determine what is morally right and good?
The good is not a product of an arbitrary decision of a mere will sporting about in a vacuum. Neither is it good because God’s will happens to yield to an alleged higher set of (Platonic) principles to which the Creator of all is subservient. Rather, the good is good because it is consistent with God’s very nature.
Gordon Lewis and Bruce Demarest, Integrative Theology, Vol. 1, (p. 234)
To read more, see my “The Divine Command Dilemma: A Christian Appraisal”