You cannot be in covenant with two different covenants as Paul explains in the book of Romans. Jesus fulfilled the law on our behalf so that we can again have our spirits restored and be in realtionship with God
1Do you not know, brothers (for I am speaking to those who know the law), that the law has authority over a man only as long as he lives?
2For instance, a married woman is bound by law to her husband as long as he lives. But if her husband dies, she is released from the law of marriage.
3So then, if she is joined to another man while her husband is still alive, she is called an adulteress; but if her husband dies, she is free from that law and is not an adulteress if she marries another man.
4Therefore, my brothers, you also died to the law through the body of Christ, that you might belong to another, to Him who was raised from the dead, in order that we might bear fruit to God. 5For when we lived according to the flesh, the sinful passions aroused by the law were at work in our bodies, bearing fruit for death.
6But now, having died to what bound us, we have been released from the law, so that we serve in the new way of the Spirit, and not in the old way of the written code. Romans 7
The authority of the law
The law points out that we are sinners and sin = death...
If we are crucified with Christ...
Christ paid the penalty of the law for us.
The authority of the law no longer holds us guilty. We are dead to the consequences of the law.. the law no longer holds us guilty because of the payment that Jesus made.
We have been released from the law...
Does that mean we continue to sin because of Jesus's grace?
Rom 6:1-2
1 What shall we say then? Shall we continue in sin, that grace may abound? 2 God forbid. How shall we, that are dead to sin, live any longer therein?
Should we that have been freed from the penalty of the law (dead to the law) continue to transgress it anyway?
No
Rom 6:14-16
14 For sin shall not have dominion over you: for ye are not under the law, but under grace. 15 What then? shall we sin, because we are not under the law, but under grace? God forbid. 16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
Notice that obedience is still required, but it is because we are children or servants of Christ.
Sin is the transgression of the law....
In the same chapter Romans 7 which you are quoting please understand these verses
Rom 7:7-14
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. 8 But sin, taking occasion by the commandment, wrought in me all manner of concupiscence. For without the law sin was dead.
Without the law sin is dead ... we don't know what sin is without the law...
9 For I was alive without the law once: but when the commandment came, sin revived, and I died. 10 And the commandment, which was ordained to life, I found to be unto death. 11 For sin, taking occasion by the commandment, deceived me, and by it slew me. 12 Wherefore the law is holy, and the commandment holy, and just, and good. 13 Was then that which is good made death unto me? God forbid. But sin, that it might appear sin, working death in me by that which is good; that sin by the commandment might become exceeding sinful. 14 For we know that the law is spiritual: but I am carnal, sold under sin.
The law is good
Sin is the enemy
We are saved from sin by Jesus's death. He paid the price of sin so the penalty of transgressing the law no longer applies.
Sure we are free, released, no longer under, and made dead to the penalty of the law but only if you are saved in Christ. Those that are not saved will be condemned by the law as sinners and death will be the result..
The law is not void. People are still guilty today.