Eternal truths exist inherent in the universe and can be known through autonomous reason, or reason unaided by God.
Eternal truths apply to all cultures/nations/societies.
“Truth” is only what is true for each culture.
Therefore what people “value” is only the product of the surrounding culture, nothing more, nothing less.
Value systems can only be understood through the medium of language appropriate to each individual culture.
Language is therefore a prisoner of culture.
The very notion of universal truth is therefore rejected.
God is “truth.”
He has revealed both specific and general standards for conduct. (These standards are revealed in nature and especially in the Bible).
Specific standard = “Thou shalt not murder.”
General standard = “Let no unwholesome word proceed from your mouth.”
Who determines the unwholesome word? Culture.
Who determines the nature of what is unwholesome? God.
Why is something unwholesome? It is inconsistent with the “goodness” of God.