Look at Jeremiah 6:16. First of all let me say that I agree that we have to work to communicate the truth in a way that those who are not in the faith can understand it. That being said when people are in the faith, there are some basics that regardless of their age, cultural background, whatever label one wishes to use to filter them, are essential. Those are the ancient ways about which Jeremiah is talking. Obedience to the Word of God is one. That assumes one knows the Word. Prayer is another. Being engaged with a community of believers in another. Being a verbal and behavioral testimony to those around you who do not believe is another.
Israel refused. As Paul says in Romans 15:4, that is recorded for our instruction.