I would say that people can be very legalistic about things in the OT which is what happened in the early church. That is why Paul did wouldn't eat meat for a time so as not to offend his hebrew christian brethren.
The OT was divided in the 10 commandments, in the moral law, social law, etc.
Basically the moral law and the social law is what we have today in our countries;
for example: if you kill you are condemned to go to jail or to die by an injection; in the Leviticus indeed if you killed then you also had to be killed, etc..
so:
The commandment: "You shall not kill"
Law: "if you kill you also must be killed"
Jesus ordered to observe the commandments:
Mark 10:17-22
17 And as he was going forth into the way, there ran one to him, and kneeled to him, and asked him, Good Teacher,
what shall I do that I may inherit eternal life?
18 And Jesus said unto him, Why callest thou me good? none is good save one, even God.
19
Thou knowest the commandments, Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor thy father and mother.
20 And he said unto him, Teacher,
all these things have I observed from my youth.
21
And Jesus looking upon him loved him, and said unto him, One thing thou lackest: go, sell whatsoever thou hast, and give to the poor, and thou shalt have treasure in heaven: and come, follow me.
22 But his countenance fell at the saying, and he went away sorrowful: for he was one that had great possessions.
ps. to help the poor was ordered by God since the OT
1 John 5:1-3
1 Whosoever believeth that Jesus is the Christ is begotten of God: and whosoever loveth him that begat loveth him also that is begotten of him.
2 Hereby we know that we love the children of God,
when we love God and do his commandments.
3 For this is
the love of God,
that we keep his commandments: and his commandments
are not grievous.
Indeed the commandment are easy to be observed (Exodus 20) despite our mortal flesh, but Jesus indeed ordered us to pray for to no fall in temptation cause the spirit is willing but the flesh is weak.
Revelation 14:12
Here is the patience of the saints, they that
keep the commandments of God, and the faith of Jesus.
The faith of Jesus was to fulfil the commandment cause he has not sin cause Jesus didn't kill, He didn't commit adultery nor false testimony, so Jesus of course observed the commandments.
There is a huge difference between The Commandments and The Law:
Commandment: Order of God
Law: Penality to all those who don't obey to the commandment
Today christians are submitted to the law of their countries which is not so far from the law of leviticus except the food and circumcision and some other stuff.
But the Commandments are different cause in our countries they teach there is no God or that you are free to believe in what you want, and it is not ordered to not tell blasphemies against God nor to have not other "gods", but these commandments must be observed in our own lives as Chsristians.
I make a typical example of people which thinks that the 10 commandments have been abolished:
The other day I saw a sister I met in a church that I used to attend; I asked her "How you doing?" she answered "I'm doing well I got divorced from my ex cause I was tired and then
God told me I had to find a new man so I did that"............. And this woman changed 3 husbands.
I am not going to judge her, but that happens when some christians don't read nor observe the commandments of God and start to believe which the will of God comes from their own sinful thoughts.
How can we be guided by our thoughts if our thoughts are not good? We have a guide written by God's finger, The Commandments.