The word gnontos means know or realize. In the original Greek there is no connotation of the word having to do with spiritual understanding or enlightenment. It is knowledge from self enlightenment or awareness.
Mankind has always made excuses, starting with Adam. This in no way has made man unaccountable before God.
https://biblehub.com/text/galatians/4-9.htm
Same word used and if that is not spiritual enlightenment, don't know what is.