A RIGHTEOUSNESS GREATER THAN RAGS:

Typically mankind endeavors to work their way into a right-standing with God, but God’s way is through faith by grace in the Lord Jesus Christ. God’s righteousness is a free gift. We cannot work our way into the right standing with God, therefore we have no bases for boasting about the position. The Righteousness of God cannot be obtained through what we have done or what family we were born into.

OUR OWN RIGHTEOUSNESS IS LIKE FILTHY RAGS:

Isaiah 64:6 ESV We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away.

Luke 18:9-14 ESV He also told this parable to some who trusted in themselves that they were righteous, and treated others with contempt: (10) "Two men went up into the temple to pray, one a Pharisee and the other a tax collector. (11) The Pharisee, standing by himself, prayed thus: 'God, I thank you that I am not like other men, extortioners, unjust, adulterers, or even like this tax collector. (12) I fast twice a week; I give tithes of all that I get.' (13) But the tax collector, standing far off, would not even lift up his eyes to heaven, but beat his breast, saying, 'God, be merciful to me, a sinner!' (14) I tell you, this man went down to his house justified, rather than the other. For everyone who exalts himself will be humbled, but the one who humbles himself will be exalted."
 
However, we as believers have been robed with the righteousness of Christ.

Titus 3:5 ESV he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit,

Philippians 3:9-11 ESV  and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith—  (10)  that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death,  (11)  that by any means possible I may attain the resurrection from the dead.

Ephesians 4:24 ESV and to put on the new self, created after the likeness of God in true righteousness and holiness.