Isaiah 64:6-7
The truth of the matter is found in the context, which extends into the next book, Jeremiah. The writings of the prophet Jeremiah, who began his ministry many years after Isaiah finished his, follow Isaiah's because of chronology. From Isaiah's time to Jeremiah's, there was no break (with the exception of King Josiah) in the downward slide of the people of Judah. A significant portion of Jeremiah chronicles the endless and increasingly perverse sins of the nation.
The following book, Lamentations, the sequel to Jeremiah, is a series of dirges, some in acrostic form, written as if it were liturgy for a national funeral. The introduction to Lamentations in the Septuagint (a Greek translation of the Old Testament) depicts Jeremiah sitting and weeping over God's recent destruction of Jerusalem due to the sins of her citizens. Thus, he is known in some circles as the Weeping Prophet. The "righteousness"—if it can be called that—found in the nation of Judah was, in God's sight, as filthy rags. This is the context of Isaiah 64:6-7.
That being said, describing a true Christian's righteousness as filthy rags ignores an enormous amount of instruction throughout the Bible that requires God's people to be holy. Notice, for instance, how the apostle Paul describes Christ's view of His church:
Christ also loved the church and gave Himself for her, that He might sanctify and cleanse her with the washing of water by the word, that He might present her to Himself a glorious church, not having spot or wrinkle or any such thing, but that she should be holy and without blemish. (Ephesians 5:25-27)
If we are not individually holy, we will not "see the Lord," Paul warns in Hebrews 12:14. Of course, our human nature taints our feeble efforts at righteousness, which are thus unacceptable to God. But when we are converted and justified, the righteousness of Jesus Christ becomes our righteousness by His blood covering our sins and Him dwelling in us through His Spirit (Isaiah 54:17; Romans 8:10; I Corinthians 1:30; II Corinthians 5:21; Ephesians 4:23-24; Philippians 1:11; 3:9; Hebrews 8:14; 10:10, 19-22).
So Isaiah 64:6-7 should not be taken out of context to apply to converted Christians. The prophet uses the phrase "our righteousnesses are like filthy rags" to describe the horrid depths of sin committed by the people of his day, when they should have known better.
Mike Fuhrer
Always Check the Context