the Isrealites had left Gods law, they were disobedient to God. Isaiah was telling them that the works of law they were performing, were useless to them....like filthy rags you throw away. 'Works of Mosaic Law'....do you know what these were?
and how did Paul use it in his letter... what is the context, who is he speaking to and why???
The oft-misquoted "Filthy rags" concept had nothing to do with the Law not working for them, what it meant was that their level of righteousness was like filthy rags, it's amazing how often Chapter 64 is cherry picked competely devoid of its actual context. He's talking about how sinful and lawless they had been, not that the law was useless to them. You seem to contradict yourself, you say that they had abandoned God's law (which they had, which was the point of Isaiah trying to bring them back), then you say the works of the Law they were performing was useless. Which one is it?
1Oh, that you would rend the heavens and come down,
that the mountains would tremble before you!
2As when fire sets twigs ablaze
and causes water to boil,
come down to make your name known to your enemies
and cause the nations to quake before you!
3For when you did awesome things that we did not expect,
you came down, and the mountains trembled before you.
4Since ancient times no one has heard,
no ear has perceived,
no eye has seen any God besides you,
who acts on behalf of those who wait for him.
5You come to the help of those who gladly do right,
who remember your ways.
But when we continued to sin against them,
you were angry.
How then can we be saved?
6All 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.
7No one calls on your name
or strives to lay hold of you;
for you have hidden your face from us
and made us waste away because of our sins.
8Yet, O Lord, you are our Father.
We are the clay, you are the potter;
we are all the work of your hand.
9Do not be angry beyond measure, O Lord;
do not remember our sins forever.
Oh, look upon us, we pray,
for we are all your people.
10Your sacred cities have become a desert;
even Zion is a desert, Jerusalem a desolation.
11Our holy and glorious temple, where our fathers praised you,
has been burned with fire,
and all that we treasured lies in ruins.
12After all this, O Lord, will you hold yourself back?
Will you keep silent and punish us beyond measure?
As you can see, the filthy rags is in reference to how lawless they had become, not that their Lawful behavior was like filthy rags as myriads change the context to.
