MORALITY IS NOT JUST OPINION BUT IS LIKE LANGUAGE - IT IS REAL IN THE WAY LANGUAGE DESPITE ALL THE DIFFERENCES IS REAL

There are many different languages but they all try to do the same thing.  Give information.  Telling somebody where the restaurant is telling somebody where the restaurant is no matter what tongue is used.  We cannot say language is just opinion for it is done differently. The purpose is the same.

Yet when cultures protect marriage for example or children in different ways people mistake the differences as saying morality is only culture and opinion and preference and justice and love are only social constructs.

Language is not real in the way a brick is but it works and that is real.  Morality is the same.

People think there is a true and universal morality, the best imaginable moral code.  They fear that thinking there is not or that it's a waste of time trying to find it is giving into relativism - morality is opinion so murder can be right tomorrow if society just prefers it to be.

But thinking there is no universal morality is simply like holding there is no and should be no universal or one true language.

The fear about relativism misses the point.  Relativism does not follow.

Languages and moral rules have to adapt with the times but change is limited by reality.  Nothing works if everybody makes up their own rules.