Let's consider the Law for what it has become to those who have Jesus' righteousness by faith. In the New Covenant, the requirement for obedience has been changed to a new standard; the law of the Spirit of life. Jesus, our eternal High Priest has entered into heaven on our behalf and the Father has sent the Spirit to us, who reproves mankind for sin, for righteousness, and for judgment and who uses scripture to write the Lord's laws and commandments into our hearts and minds. We are, by the Spirit's guidance, to strive at making our practical righteousness to reflect our imputed righteousness. So, for us, the OT's letter of the law has now become a simple guideline for what is sin. But even so, in the NT, the Holy Spirit leads us to follow the law of the Spirit of life, a standard of obedience that reflects Jesus' obedience; where the Lord looks to the heart and its intent and not just in our outward behavior and where, whatever is not of faith, is sin. That the New Covenant has no curse for sin, allows us, at any time, to forget those things that are past and press toward the mark for the prize of the high calling of God in Christ Jesus.
Rom 7:12 "Wherefore the law is holy, and the commandment holy, and just, and good."
Rom 8:2 "For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death."
Heb 7:12 "For the priesthood being changed, there is made of necessity a change also of the law."
Jn 16:8 "And when he is come, he will reprove the world of sin, of righteousness, and of judgment."
Heb 12:11 "Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby."
Jn 16:3 "Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come."
Phil 3:13, 14 "Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus."
Heb 10:6 "This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them."
Rom 14:23 "And he that doubteth is damned if he eat, because he eateth not of faith: for whatever is not of faith, is sin."