"All our righteous acts are like filthy rags." (Isaiah 64:6)
Isaiah 64 is an obvious old covenant scripture when we read the whole chapter, yet we use part of a verse from it (above) for modern day evangelism. We take what one group of people said about themselves, it is not even God speaking, & apply it to all of humanity. It does not even say their view of themselves is accurate.
This does not refer to all of mankind. If God viewed all of mankind's righteous acts apart from Him as filthy rags He'd be unjust. On top of that this is never the way the Old Testament pictures God. There are countless places where God loves people's righteous acts in the Old Testament.
"How then can we be saved? All of us have become like one who is unclean, and all our righteous acts are like filthy rags (garments); we all shrivel up like a leaf, and like the wind our sins sweep us away." (Isaiah 64:5-6)
Why do we need clean garments of righteousness? Is it because God is a stickler & will murder anyone who doesn't meet His standards? No! No! NO!
"The devil holds the power of death" (Hebrews 2:14). "The devil prowls around like a roaring lion looking for someone to devour" (1 Peter 5:8). When people are unclean the devil catches their scent. In the old covenant there were many scent based offerings to throw Satan off. We need righteousness to protect us from death. Sin has earned us death (Romans 6:23) but righteousness earns us life (Proverbs 10:16).
We don't need righteousness to approach God. Jesus is God & even prostitutes approached Him. It wasn't God's choice to blind men because they failed to meet His high standards. Sin was what blinded mankind to God. Jesus came to restore sight to the blind. If He was the one who made them blind in the first place He is double-minded & cannot be trusted.
The universal truth of the opening verse is that we cannot, by our deeds, clean ourselves of unrighteousness. We cannot clean ourselves of unrighteousness at all. People's righteous acts are like filthy rags, NOT in the eyes of God, but because they cannot cleanse us, they just rub the dirt around. When we are saved our spirits are "cleansed of all unrighteousness" (1 John 1:9) & Satan can no longer touch us (1 John 5:18).
The world view of "God demands we live up to a standard & you don't measure up" IS FALSE. Many people reject God because they can plainly see what Christians are really saying while the Christians have no clue. They reject Him because Christians have presented Him as a self-centered worship demanding maniac who will torture you if you don't join his side. He's pictured like a ruthless dictator who doesn't really care about human life at all, that he literally values nothing about us except what we can do for him! That he not only sees us as valueless but he sees even the best things we do as filthy as bloody menstrual rags! Where is the good news there? This is essentially what the "our righteousness is filthy rags" gospel says, "You make God want to barf but he'll slowly clean you up so he doesn't have to smell your rank butt for all eternity."
It is true that our deeds cannot clean us, they cannot save us. But please stop using this scripture to define how God views humanity. This is not right, especially after the cross! Righteousness is necessary for safety from sin, Satan, & death. God loves righteousness, even that done by those who don't know Him. On judgment day it says God will judge people by their deeds, it does not say He will judge them by their sins (Revelation 20:12).
If we truly believe that men choose death, rather than God condemns men for rejecting Him.. If we truly believe that God loves the whole world, God is love & love keeps no record of wrongs.. maybe we'd see things like this..
God "stores up wrath for the day of judgment" for the sake of justice (Romans 2:5) so that those who hate Him, even after He offers them one more chance on that judgment day, can justly have the second death (which is annihilation) that they have chosen. Why does Revelation 20:12 say God judges by deeds? Why oh, why wouldn't it say He judges them by sins? Because He has already taken the sinful deeds of the world away. "The sting of death is sin" (1 Corinthians 15:56). God wants to take away that sting as much as He can, even for those who reject Him! He judges them by their deeds to ease the sting of death that their sinful condition has earned them.
Long standing doctrines have caused us to be blind to the plain texts & contexts of scripture seeing only the details, assumptions, & interpretations of those doctrines when we read scripture. This is true for those who believe the doctrines & many of those who don't. Those who embrace the doctrines are blind to the truth. Those who reject the doctrines often reject the scriptures too. But there is truth in the scriptures & it is good news. The good news of freedom, salvation, love, & mercy.