For a long time the culture held up with the glue anyway, even tho not everyone was overtly Christian. It was a pretty good way to live (and if you did otherwise you kept it more or less to yourself). Now the glue is gone and everything is falling apart.
I point out to my children that what their Dad and I tell them is wrong is also objectively stupid. Best odds to avoid a bad outcome is to do what we say. We get plenty of opportunity to point out examples, too. (Taylor Swift dating a Kennedy comes to mind, right now ... makes her a possibility in the Dead Pool for the next year.)