That is equated with the robe of self-righteousness. It was possible before Adam fell. He could earn some degree of righteous character by obedience to God's law. Because he sinned our natures today are fallen and we cannot make ourselves righteous. We cannot perfectly obey the holy law.
Nobody here has perfect patience.
But Christ has made a way of escape for us. He offers to take our sins and give us His perfect righteousness. If you accept Him as your Savior, then sinful as your life may have been, for His sake you are accounted righteous. Christ's character stands in place of your character, and you are accepted before God just as if you had not sinned. So you see why Christians today stand more righteous than Adam before he even fell.