Outside of these kind of websites where they exist for theological debate, in the real world, it would be the most pointless exercise to tell anyone they must obey the TC for example.
Every Christian I have ever known would say in their mind they know God does not want them to steal, commit adultery, bear false witness, murder, covet, take God’s name in vain etc. And every Christian I have ever known would say in their heart(the flesh is another matter) they do not want to do those things.
‘I will write my laws in their minds
And place them on their hearts.’
So it truly is a pointless exercise to tell any believer for example ‘’you must obey the TC.’’ Applicable law if you like is part of a person’s spiritual dna in Christ, that’s the NC. It is no longer an external law written in ink or engraved in stone, but an internal law, in believers most inward parts
Pointless to tell non believers also, they only want to live according to their own particular moral compass, not God’s.
The phrase ‘’you must obey the TC, is for a time before the NC came into existence, a time before God wrote the law in peoples minds and placed it on their hearts he wants them to follow. So, in reality many in truth want to follow an OC mindset. But as Jesus said:
Many after drinking the old wine don’t want the new, for they say : ‘The old is better’ Luke5:39