God was calling these people as He did in Haggai and in so many other places in the Old Testament to "consider their ways." Jesus spent His entire earthly ministry calling people to examine themselves in light of the gospel and their need of a Savior.
Stand ye in the ways, and see... To stand, we must stop. We race along in our lives, navigating the traffic and seldom looking back. God is calling us to stop now and then and examine our lives and our paths. Are we really following His direction? Are we obeying His instruction? Are we even listening to His voice?
Do you need rest for your soul? You can find it in the old paths. This reference has nothing to do with style of ministry. The old paths were the forgotten ways that the Israelites had walked. They had previously followed the laws of God, but now they were walking in the ways of the pagan nations around them. Have you left the simple life of faith? Pull over and stop a minute. Examine your life and see whether you are following God and His Word or the expectations of those around you, or even selfish ambitions. In order to find rest for your soul, you must first see that you are on the wrong path, and then ask God to show you the good way. Look to His Word, and walk therein. Don't be like the stubborn people referred to in this verse. But they said, We will not walk therein. They chose a path that ended in weariness and desolation.