Putting it simply.... the law is not made void in the new testament. We are saved by faith in Christs righteousness, and Christ kept the law perfectly. His death did not change the law, He paid the price for transgressing it, freeing us from the law.
Free from the curse if we repent and believe.
Not free to continue in sin.
The moral law has not changed but we can know by faith that the price is paid in full.
If I'm guilty of speeding and get a fine (according to the law). Jesus wants to help me so He.....
.....changes the law so everyone is free to speed.
.....pays the fine for me.
Jesus didn't change the moral law.
Nowhere in the bible is the Law referred to as the "moral" Law. That is a word made up by Pharisees to lock in their circular reasoning and try to trap people into the same silly philosophy.
If the law were, in fact, a moral law then much of the New Testament and words of the Lord are non-sensical.
Colossians 2:16-17
16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:
17 Which are a shadow of things to come; but the body is of Christ.
If the law is a moral law then there is no escaping Judaism and all its laws. The law absolutely judges those who are under it. You are not moral if you don't follow a moral law. Resting on saturdays was written on stone. How could it be said to let no man judge you on it if it is a "moral" law??