"Come back," God says through the prophet Isaiah, "Come back home, Come back to a place, Come back to a way of living."
We modern readers may or may not have been separated from a physical place. Few of us have known forcible exile. Yet, separation from God and separation from God's commands may be more familiar to us.
I have read and reread Isaiah 56:1, "Maintain justice, and do what is right, for soon my salvation will come, and my deliverance be revealed." Is he saying that our actions will precipitation our salvation? Is he saying that we need to prepare for salvation by living like saved people? In either case, I get the message that we are supposed to maintain justice and do what is right.