The Laws of the Old Testament can be put into three categories as mentioned: Civil, Ceremonial, and Moral.
I dont know about you, but I am an American citizen. I live under the American Civil law, and glorify God by obeying the "law of the land." The Civil laws of the Old Jewish state really have no bearing on me, a gentile outside of that country.
Ceremonial Law, Sacrafices, worship etc. Well first off, most of these apply to the Levitical priesthood, which I am not a jew, and have to access nor right to. But most importantly, Hebrews tells us that
HEBREWS 10:11-22 11 And every priest stands ministering daily and offering repeatedly the same sacrifices, which can never take away sins. 12 But this Man, after He had offered one sacrifice for sins forever, sat down at the right hand of God, 13 from that time waiting till His enemies are made His footstool. 14 For by one offering He has perfected forever those who are being sanctified.
15 But the Holy Spirit also witnesses to us; for after He had said before,
16 “This is the covenant that I will make with them after those days, says the Lord: I will put My laws into their hearts, and in their minds I will write them,”[c] 17 then He adds, “Their sins and their lawless deeds I will remember no more.”[d] 18 Now where there is remission of these, there is no longer an offering for sin.
Hold Fast Your Confession
19 Therefore, brethren, having boldness to enter the Holiest by the blood of Jesus, 20 by a new and living way which He consecrated for us, through the veil, that is, His flesh, 21 and having a High Priest over the house of God, 22 let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water.
Please read the book of Hebrews, it is really great in tying the Old and New together.
So, Christ is the High Priests, he has Achieved the righteousness of the Law for us (Which we could never ever do). As told in the books of Acts, Peter reasons about gentile disciples being taught to following the Laws of Moses.
Acts 15:6b-12 Peter rose up and said to them: “Men and brethren, you know that a good while ago God chose among us, that by my mouth the Gentiles should hear the word of the gospel and believe. 8 So God, who knows the heart, acknowledged them by giving them the Holy Spirit, just as He did to us, 9 and made no distinction between us and them, purifying their hearts by faith. 10 Now therefore, why do you test God by putting a yoke on the neck of the disciples which neither our fathers nor we were able to bear? 11 But we believe that through the grace of the Lord Jesus Christ[a] we shall be saved in the same manner as they.”
See how he calls the law a "yoke which we neither we nor our fathers could bear"
Paul tells us in Romans 3:20
For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin.
Keeping that law can NOT save anyone, but breaking the law is Sin and condemns the whole word before God.
So Paul Clarifies for us. Romans 4:3
What does Scripture say? "Abraham believed God, and it was credited to him as righteousness."
So even from as far back as Abraham, being made right with God has come through Faith!
For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; 9not as a result of works, so that no one may boast.
Putting faith in our works and our ability to "keep the law" is actually a dangerous snare called "legalism." It is a snare because what we are doing is putting out faith in OUR OWN WORKS as opposed to in the FINISHED WORK of CHRIST.
God's MORAL LAW.
Gods moral law is traditionally spelled out in the 10 commandments, but is often found in other places of scripture also. These let us know about Gods Character, and his requirements for human conduct.
The bible says in 1 Pet 1:16
since it is written, “You shall be holy, for I am holy.”
God requires purity on the inward parts
psalm 51:6 Behold, You desire truth in the inward parts,
Gods Moral law shows us Gods character, and helps us to see ourselves in truth. (as sinners who have violated the law). The Fact is that Telling Lies is Wrong! Stealing is Wrong! Coveting is Wrong! Adultery is Wrong! Murder is Wrong! and such are the commandments.
They are holy and good, but they can't save you, because we have all already sinned and broken Gods law. Some people comfort themselves saying "Well I havent ever murdered anyone, im not really that guilty."
But the bible says in James 2:10
For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it.
The law stands and accuses us, we can't use it to clean ourselves up! We need someone to pay the penalty for us, God demands Justice!
This is what Jesus did on the Cross.