If our righteousness is as filthy rags to God, just how can anyone consider that they would in any way make one worthy to then receive and continue on in grace?
The best we can do is then the same as doing nothing.
All of us have become like one who is unclean, and all our righteous acts are like filthy rags; we all shrivel up like a leaf, and like the wind our sins sweep us away. Isaiah 64:6