Your eisegesis is tragic. Of course the law isn't sin. The law shows us what sin is.First let me say that God had Peter to clearly warn us about some of Paul’s writing. (2Peter:3:15-16) (v.15) And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you; (v.16) As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. Now let us take heed to this warning, we can’t ignore all the bible and just concentrate on a hand full of verses out of the writings of Paul. Because some of Paul’s writing is hard to be understood.
That Law Paul is talking about in verse 4-6 is referring to the animal Sacrificial law, Paul explained this in; (Hebrews 10: (v.1) For the law (what law, the law of animal sacrifice?) having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect. (v.9) Then said he, (Jesus) Lo, I come to do thy will, O God. He taketh away the first that he may establish the second. (v.10) By which will we are sanctified through the offering of the body of Jesus Christ once for all. 11 And every priest standeth daily ministering and offering oftentimes the same sacrifices, which can never take away sins: 12 but this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God; 13 from henceforth expecting till his enemies be made his footstool. 14 For by one offering he hath perfected for ever them that are sanctified.
The point that is not understood is that we all have sin, but until Jesus came, there was no way of getting out from under your sins. So God institute a Priesthood and laws that went with the priesthood to control the sinning, and so the Lord use animal Sacrificial laws, even though it could not remove sins.
When Jesus died on the cross that was the end of the first covenant, which consisted of the blood of animals and the keeping of God’s commandments. And his death also brought in the second covenant, which consist of the blood of Jesus and the keeping of God’s commandments. (v.18) Now where remission of these is, there is no more offering for sin. In other words, no more animals are going to die for your sins. (20) by a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh; (21) and having an high priest over the house of God; (v.26) For if we sin willfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins.
Now do we understand what’s being said here? If you sin willfully after you have knowledge of what the truth is, no more animals are going to die for you. (v.27) But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries. Now if you are being deceived into believing that once you are under God’s grace you no longer have to keep his commandments, all you have to look forward to is the day of judgement and the lake of fire (fiery indignation).
Now let's see why it's hard for some people to miss understand Paul writing, we will see a change in the law, Paul will talk about the Royal law (Commandments) in the next verse in Romans 7: (v.7) What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, THOU SHALT NOT COVET.
Paul asked a question, is the law sin? He said God forbid, he said the only way that he knew what sin was, was by the law.
(v.12) Wherefore the law is holy, and the commandment holy, and just, and good. Why in the world would a Christian want to do away with something that God said is holy.
Paul says in (Rom. 4:15) Because the law worketh wrath: for where no law is, there is no transgression. If there is no law there is no sin.
You should care pay attention to what Paul wrote to the Corinthians: "Are we beginning to commend ourselves again? Surely we do not need, as some do, letters of recommendation to you or from you, do we? You yourselves are our letter, written on our hearts, known and read by all, and you show that you are a letter of Christ, prepared by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets that are human hearts.
Such is the confidence that we have through Christ toward God. Not that we are qualified of ourselves to claim anything as coming from us; our qualification is from God, who has made us qualified to be ministers of a new covenant, not of letter but of spirit, for the letter kills, but the Spirit gives life.
Now if the ministry of death, chiseled in letters on stone tablets, came in glory so that the people of Israel could not gaze at Moses’s face because of the glory of his face, a glory now set aside, how much more will the ministry of the Spirit come in glory? For if there was glory in the ministry of condemnation, much more does the ministry of justification abound in glory! Indeed, what once had glory has in this respect lost its glory because of the greater glory, for if what was set aside came through glory, much more has the permanent come in glory!" 2 Corinthians 3:1-11
You need to get away from Romans 7! There is a lot more to the New Covenant, which is by the Spirit, not by the law. It saddens me that you feel one must abide by the written law, which clearly brings death. You have clearly missed the foundation of the New Covenant! Jesus paid the ultimate sacrifice that freed us from the law (which nobody could keep!) and enabled us to become children of God. You will never be acceptable to God by trying to keep the law!!!