It is interesting the every culture has a sense of morality, and that no matter how “primitive” they are, they acknowledge some sort of Creator. I am not aware of any past culture that has been found to be atheistic. Every culture acknowledges God because the knowledge of His existence is manifest through the conscience, as well as through creation (see Rom. 1:19–21).
The word “conscience” comes from two words and means “with knowledge” (con means “with” and science means “knowledge”). Here is the dictionary definition: “knowledge within oneself, a moral sense; lit. with-knowledge.”
Consider the experience of a minister who went to Papua New Guinea and met with a tribe that had no prior contact with Christianity. He asked if they believed that certain behaviors were wrong. They admitted that things like stealing, cannibalism (which some of them were practicing), and adultery were wrong. When he asked how they knew it was wrong, they said they knew it in their being…in their heart. That’s the conscience. With no contact with the Bible or with Christians, instinctively they knew the difference between right and wrong.
However, let’s say that you are right—that it is society and not God that entirely shapes the human conscience. Let’s imagine that a man has been rescued by authorities after 20 years of being raised by wolves. He is found to be intelligent and completely sane, but has had no moral instruction from any human being in those 20 years.
He is cleaned up, given a nice suit, and taken to New York where he is overawed by what he sees. He is still given no moral instruction. When he is left alone, the first thing he does is find a pretty young woman. He rapes and murders her, then he steals her money and is captured while spending it.
In court, his attorney’s defense is that he didn’t know right from wrong—society had given him no moral instruction. Is the judge going to let him go? Of course not, because although the human conscience may be influenced by society, it is not given to us by society. We each have the moral Law written on our heart, and it speaks of issues of right and wrong. The conscience is given to us by God, so that every sane human being intuitively knows that some things are “right” and some things are “wrong” regardless of what was taught to us. That is why we will all be without excuse on the Day of Judgment.
1 Corinthians 8:10 For if anyone sees you who have knowledge eating in an idol’s temple, will not the conscience of him who is weak be emboldened to eat those things offered to idols?