The Bible itself does not make the neat distinctions of moral/ceremonial/civil. It does, however, appear to make some distinctions within the Law...
Paul speaks of the "law of commandments expressed in ordinances" and says that it's abolished in Ephesians 2:15. This appears to refer to ceremonial, cleanliness regulations surrounding temple worship.
In Colossians 2:16-17 Paul says that food laws and festival laws are a shadow, the substance of which is Christ. The presence of Christ therefore fulfills these particular aspects of the law.
Hebrews 8 talks about how the temple and levitical priesthood is part of an old covenant and is obsolete now that a new covenant has come. Christ is the mediator of the new covenant and is the true priest who serves in the heavenly temple. So the levitical priesthood has passed away.
But other parts of Scripture affirm the eternal significance of the Law...
In Matthew 5:17-20 Jesus says that he came not to abolish the Law, but to fulfill it. He then goes on to talk about moral commands of the Law in the rest of his sermon.
In Romans 3:31 says that Christians are to uphold the Law, presumably speaking of the moral commands of the Law.
So the ceremonial/moral/civil distinction is artificial but it is useful. There appears to be ceremonial, civil, and moral aspects to God's Law. The ceremonial and civil appear to have adjusted in their meaning for us in light of Jesus Christ and the nature of his church. For example, since he is our priest we no longer require a levitical priesthood. Also, since the church is not a nation-state we must adjust the meaning of commands related to Israel as a nation state (such as capital punishment). But the moral commands of the Law don't seem to need any adjusting in light of Christ so we keep them untouched.
Well, I agree with most of what you said. But I do not believe the separation of the laws is artificial. I believe that the Bible does teach this three fold structure of the Law. Some folks just think that Law is Law when there are different kinds of laws with some being more important than others. Obviously the Moral Law is superior to the Civil and Ceremonial laws (even though they are also important). For just obeying the Civil and Ceremonial Laws while neglecting the Moral Laws would be disasterous for a believer.
To gain further insight on this topic, I decided to read several forums and articles on this topic, and I came across an interesting book that comes highly recommended. The author believes there is strong biblical support for the three fold structure of the Law. So I ordered the book through Amazon to learn more. It is called: "From the Finger of God: The Biblical and Theological Basis for the Threefold Division of the Law."
In one article I was reading, another author (Named: Thomas Aquinas) pointed out that we can see the three fold structure of Deuteronomy 5:31 and Deuteronomy 6:1.
"But as for thee, stand thou here by me, and I will speak unto thee all the
commandments, and
the statutes, and
the judgments, which thou shalt teach them, that they may do
them in the land which I give them to possess it." (Deuteronomy 5:31).
"Now these
are the
commandments, the
statutes, and the
judgments, which the LORD your God commanded to teach you, that ye might do
them in the land whither ye go to possess it." (Deuteronomy 6:1).
Another good point that is made by another author (Kaiser), as well. According to him,
the frequent appeal for mercy and not for sacrifice (Hosea 6:6; Jeremiah 7:21-23; Micah 6:8; 1 Samuel 15:22-23; Psalms 51:17) indicates “a deliberate priority and ranking in the legal injunctions that had been given by Moses.” This may explain why the Rabbis distinguished
between “heavy” and “light” commands, a distinction apparently accepted by Jesus (Luke 10:28; cf. Matthew 22:34-40; Mark 12:28-34). Moral commands obviously fell within the
“heavy” category.
...
