God asked Israel to have a faith in Him that was clearly demonstrable. The covenant instructed God's people on how they should love. The social structure would be impacted by their faith. They were to "keep justice" as an action always before them. God is just. He treats nobody unfairly. And He will act in justice. As God acts, so should we. We should not be idle when injustices abound. We should be just with people even if they are not so with us.
This was one way to "do righteousness". Basically, the Jews had a codified list of what was to constitute righteousness before God in the way they lived. They knew it as The Law. And the prophets called them to renew themselves to its standards. They could repent, renew, and do what God says is good. And the change that came with that would be sweeping. It could turn the people away from the pains for the consequences of their disobedience and into the nation that existed to point the world to the greatness of The Lord their God.
There was a clock ticking with them... a chance to know the salvation of God coming to them. They would not stay captive in a foreign land forever. God would lead them back into the Promised Land as His covenant people again, and they would live in justice and righteousness. But the time to do that was not in the future. The time to do that was now! God wants us to be sure the NOW is always the time to live for Him. Today He is known. Today we live for Him so that His deliverance will be revealed.