I think probably someone needs to answer the original question, without bringing the OT into it. (I'm just guessing nobody has, because I know how threads like this go.)
The primary laws of Jesus are :
Love your enemy; don't bother with your friends
Don't get divorced; don't even look at another woman
Honour your parents
Pray in secret
Give in secret
Resist not evil
Work your wonders in the most corrupt areas
Love God with all your heart
(We are uncertain about slave and homosexuality laws. Possibly the love idea was supposed to go viral and undermine all Hebrew laws.)
Be incredibly poor, and don't trust wealth; give it all away
Don't argue with your brother
Avoid persecution by agreeing with your persecutor
Don't wash your hands
Identify corrupt trees from their fruit
When we look through that list, it's difficult not to see some as hyperbole, but there is also an idealist truth to them, that Jesus implies strongly that you have to follow. He is, after all, the guy who is saving you from your sins by giving you the proof that God was real. Since you know God is real, you have no excuse but to follow his laws perfectly. Your demonstration of faith, is to show that you believe Jesus was real, by doing exactly what he said.
However, looking at the laws from a modern perspective, where we have tried to live by the laws, and found that some of them are intellectual ideals, similar to communism, that don't really work. Nobody has really done the original research that you can pacify an enemy by loving them. Punching them in the face seems to work so much better. Evil dictators need to be stood up to, not ignored, apparently.
Giving in secret also seems to be a problem, because nobody will know you are doing it, so a culture of not doing it will rise.
Divorce laws are a problem, because people seldom can stand living with the same person, without fcukin around. There appears to be no decent reason why you should not fcuk around, either.
His idea that we should not bother with friends, and instead delve into the most corrupt areas, also seems not to "work". The most corrupt areas always seem to remain corrupt and hopeless. Bush regenerators have come up with the idea that you start from the least corrupt areas, and one criminologist has suggested the "Broken windows theory", where you start by cleaning up trivial offences first. It stands to reason that USA is going to be no help to 3rd world countries if its own country is full up with bitterness moral bankruptcy. The way we seem to help people now, is by using laws of capitalism, because we can find no other way.
Being incredibly poor does not work in capitalism, unless some church supports you to do your work. As such, not all people can be Christian. Most have to keep the economy going. The ideas of Christianity were apocalyptic; with no thought for the future - yet here we are. (Jehovah's Witnesses are still waiting for the end which is not coming.)
Judging not seems not to generally work, except as a way to gain smelly friends.
So, the laws of Christ are an interesting ideal that nobody believes actually work. Nobody has faith in him, any more than they'd have faith in a Marxist philosopher. But we do agree with the general proposition that we should try to be nice to people, until they ask for money.The law of capitalism is inviolable, apparently.