In recent dialogue with a couple of atheists, the moral argument was given for the existence of God. The argument says that there exists an objective moral law, therefore there has to be a moral law giver, a prescriber of these morals. The atheists of course always deny this, but as is always the case, they ultimately hold that some things are morally right and wrong, and all attempts to deny the moral argument end in contradiction.
The two most common arguments given against an objective moral law are herd instinct and social convention. Regarding herd instinct, the atheists hold that one cause of humans having morals is due to animal instincts developed to enhance survival. They feel that if they can show that animals show some sort of assistance to another member of their specie that they have refuted the idea of our behavior towards others as being truly moral. But this is untrue, for 1) morals involve choice, and there is no choice in instinct; 2) morality is often a conscious choice to go against our instincts; 3) if instincts equaled morals, then all instincts would be, by definition, moral. Thus the praying mantis who eats its mate would be equally moral as the bird who mates for life. Such a view destroys any concept of objectivity, choice, or right and wrong. All behavior is merely behavior. If I say that stealing your stuff is human instinct expressed by young humans, you have lost the right to say that someone stealing your stuff is wrong. 4) The fact that we have a sense of “ought” destroys the instinct argument, for instinct never gets to a sense that things ought to be different than they are; 4) there is no objective reason that animals could not make moral choices, for not all of animal behavior is instinct, but some is learned. Thus the argument from herd instinct fails.
The argument from social convention, or social contract, says that all morals are merely agreements between members of social groups to ensure mutual survival. This is untrue, because 1) everyone who expresses this view must hold that all social conventions are moral, and no one believes this; 2) there is no objective way to determine what constitutes a social group. Is it a family? a clan? a town? a country? Universal human experience tells us that social groups have conflicts, often ending in war and death. So there are obvious practical limits to the edge of social groups, but no objective way to determine where these are. This lack of definition of social groups limits the application of the theory so severely as to make the theory mostly useless.
Perhaps the most severe flaw of the social contract theory seems to be the one to which the atheist and skeptic are most blind. The first response above says everyone who expresses social contract theory of morals must hold that all social conventions are moral, and no one believes this. A main pillar of atheist and skeptical criticisms of Christianity is that the Bible presents ideas which are morally abhorrent. Well, if the social contract theory of morals says that all social definitions of behavior are moral, then the social definitions in the Bible must be right for that culture. The skeptic has pulled the rug out from under his own argument, for in reality, they teach that the things in the Bible are truly wrong, i.e., objectively immoral. If the things in the Bible are immoral, the main premise of the moral argument is found true; if there are no objective morals, the skeptic has given up the right to criticize any and all human behavior, including the acts in the Bible. But more importantly, social contract theory gives up the right to criticize any act by a member of another social group, no matter how awful. Thus this view turns out to be the most morally abhorrent view imaginable.
That the atheists and skeptics do not grasp this huge flaw in their reasoning is astounding. They continue to hold that things in the Bible are truly wrong, but turn around in the next breath and deny the existence of any concept of objective morals. The Bible is shown true when it says that those who are not regenerated by God are blind…..they are described in Ephesians 4:18.