Let me answer the question for you. You do not know anyone who perfectly obeys the letter of all Christ's commands in the Gospels, and neither do you, so the following is just pat words, based on the perfection no one ever achieves:
''And this letter of the law is fulfilled as we walk in the new life that is in Christ according to the
standard of the New Covenant which is by grace. We need to have the law related perfectly (in the letter) in order to see how the life afforded to us by grace is able to fulfill it. No more need to compromise because of the weakness of the flesh because of the "finished" work of Christ that if walked in...matches His walk perfectly.
What we have by
abiding in Christ is a walk in supernatural grace. We need to tighten the restraints of the law...establish law (as Paul says in Rom. 3:31) Otherwise we are just bringing condemnation on people for doing what is right...albeit imperfectly. Grace empowers us to fulfill the law in the letter of the law...because it is able to do so perfectly...as Jesus did.
So then...
the letter kills but the Spirit gives life! You can't have one standard without the other.
Here is that dual statement again...
Romans 6:23 "For the wages of sin is
death; but the gift of God is
eternal life through Jesus Christ our Lord''