God covers us with His own divine righteousness.
"I will greatly rejoice in the LORD; my soul shall exult in my God, for he has clothed me with the garments of salvation; he has covered me with the robe of righteousness, as a bridegroom decks himself like a priest with a beautiful headdress, as a bride adorns herself with her jewels." ( Isaiah 61;10)
God covers us with his own divine righteousness by his grace through his faith. Here is the Old Testament picture of imputed righteousness, the righteousness of Jesus Christ credited to the Christian, not based on anything we have done, and is the heart of the New Covenant. "For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God." (2 Corinthians 5: 21)