The Lord is telling them in verse 16 to stand in the old ways and ask for the old paths where they used to walk. They said that they would not walk therein. They told God that they would not do as He wanted them to do.
What are the old ways today? They were the times when God was respected and held in highest honour, when sin was sin and people were concerned about what they saw, heard and listened to. We too, seem to be people that have forgotten God, and because we have, our end will also be disastrous.
God is saying the same thing to us today as He said to the people of Jeremiah's day. Are we listening? Are we heeding the warning? It's time that we take a look at our world and the sin that's in it. It's time for us to start being people who will stand up for what is right and recognize sin for what it is. We may not be able to do much on a world wide scale, but we can do everything we can where we are.