1Cry aloud, spare not, lift up thy voice like a trumpet, and shew my people their transgression, and the house of Jacob their sins.
2Yet they seek me daily, and delight to know my ways, as a nation that did righteousness, and forsook not the ordinance of their God: they ask of me the ordinances of justice; they take delight in approaching to God." (Isaiah 58: 1-2)
Isaiah 58, one of many telling passages in the Old Testament prefiguring the coming of Christ Jesus, focuses on the Sabbath Day, and the need for the Israelites to respect and rest once again.
Isaiah preached these words of warning and rebuke to a nation suffused with self-righteousness, very much like Israel during the days of Jesus' earthly ministry.
The key statement stands out with "As a nation that did righteousness".
Yet throughout the Old Testament, the LORD God has to remind His people:
"They are all gone aside, they are all together become filthy: there is none that doeth good, no, not one." (Psalm 14: 3)
"And enter not into judgment with thy servant: for in thy sight shall no man living be justified." (Psalm 143: 2)
"For there is not a just man upon earth, that doeth good, and sinneth not." (Ecclesiastes 7: 20)
So, let us give up any pretense that any of us are righteous or achieve rightoeusness through something that we do.
We are made the righteousness of God in Christ, because Jesus became sin (2 Corinthians 5: 21)
Righteousness is a gift, which we keep on receiving. If it is a gift, then you and I do not earn it, cannot earn it.
Righteousness is something that Jesus is for us, too (1 Corinthians 1: 30)
Before the final prophets would announce the coming of Elijah and the Great Day of the Lord, Isaiah had to remind them that they cannot do righteousness.
That comes from God alone, and in Christ we have this righteousness today and forever more.