Viewed against the span of Christian history, Dispensationalism is very new, and Covenant Theology only a little older. Though both, along with the General Baptists, have deluded themselves and claim they have been around since apostolic times, if not earlier.
As I have written many times, I am in closer agreement with Covenant Theology, though I have many disagreements.
I certainly disagree with the way they often simply make things up. Then they attempt to justify what they make up using classical philosophy while calling those who disagree with them biblicists (a term I embrace, but not in the form of the grotesque caricature they use as a straw man) antinomians, and other types of heretics.
In truth (and acknowledged by some of their own, such as Bavinck[1]) the development of Covenant Theology had at first a singular purpose: to preserve paedobaptism. To accomplish this goal, they developed the concept of a single over-arching covenant (of grace) that spans human history. This is in spite of the fact that the bible makes no reference to such a covenant, and in fact makes plain reference to the old and new (and better) covenants as being utterly distinct. But only simpleminded biblicists point that out, for we are somewhat incapable of invoking Plato to tease out new doctrine that is not only not present but actually superficially (to us chowderheads) at odds with scripture.
Once you have a single over-arching covenant, you are forced into a theology that stresses continuity. Over stresses continuity—all so that infant circumcision can morph into infant baptism.[2] (Dispensationalism, on the other hand, over-stresses discontinuity.)
We must admit that covenant theologians are among the cleverest people who delve into theology. When they invent something to fit their theology, they make it sound like something that you could not possibly be against unless you were a minion of the antichrist.
One complex invention of Covenant Theologians are the (not found anywhere in scripture—sorry that’s again the biblicist within) arbitrary divisions of the law. They were created when their zeal for continuity came face to face with the reality of all the covenantal laws the Jews were under. We want continuity, but we don’t want circumcision!
Well, to satisfy their continuity lust, they relabeled the Decalogue the “Eternal Moral Law of God” and the other laws became “ceremonial” or “civil” or “positive”. This satisfied most (but not the theonomists, who in some ways are the most self-consistent covenant theologians) as it allowed them to be “as continuous as they could be.”
Some even argue the that Decalogue was the law written on the hearts of all people, even before the fall. But there is not one jot or tittle of scripture to support this.
The Decalogue is never referred to as the moral law of God, let alone the fully revealed eternal moral law of God. It is referred to as law of the covenant, and the box that carried around the tablets as the ark of the covenant, not the ark of the moral law.
Here we summarize some distinctions:
Covenant view: There were many types of laws given to the Jews. There were positive laws, there were ceremonial and civil laws, and there were moral laws. And the moral laws are either entirely found in the Ten Commandments, or there is a subset of the moral laws, those that are eternal, that are the Ten Commandments. And these eternal moral laws (since they are eternal) simply must be the laws that were written on hearts going back to the garden. Jesus, in the Sermon on the Mount, is not giving new law, he is merely correcting bad teaching.
Biblicist View: All of God’s laws are moral. Jews were not morally obliged to obey the Decalogue and ceremonially obliged to obey the law on circumcision. They were morally obligated to obey both and all other laws of their covenant. These old covenant laws went away with the onset of the new covenant, and Mosaic law was replaced by a new and better revelation of the law given by Jesus.
It is actually quite strange, when you think about it, to call only a subset of God’s law moral.
Interestingly enough, the great confessions are quite revealing in this matter. For example, in the WCF we read:
Beside this law [the Decalogue], commonly called moral, (WCF 19.3)
Even by the rather weak standard of scriptural proof texts for the pronouncements of the confession, none is provided to justify renaming the Ten Commandments as the moral law of God. The only justification provided is that it was “commonly called” such. By whom we are not told. And since the confession was written, the rather mild “commonly called” has evolved an understanding more in line with: “Thou Shalt Call it the Eternal Moral of God and Nothing Less.”
[1] “The covenant was the sure scriptural objective ground upon which all the Reformed, together and without distinction, based the right to infant baptism. They had no other deeper or more solid ground." (Herman Bavinck, Reformed Dogmatics.)
[2] That’s not to say I disagree with infant baptism. I disagree that the justification for infant baptism is connected to circumcision.