Hello DHC, a very interesting post, and one you must have thought carefully about. I certainly agree with your first statement, that the covenants ought to be understood...they are most assuredly the basis of many doctrines.
What you share in your post is also shared by most churches today. It is very popular theology...the fruits of which we read constantly on this and other forums in the manner in which modern Christians approach the law, obedience, and ultimately, salvation. The question which must be asked: is the Ten Commandment Law of God the old covenant that was abolished at Calvary? To this question I will now give my answer.
First, I can only agree that there are some verses that refer to the Ten Commandments as a covenant. But is it the covenant that was abolished?
It is just as important to understand what the Old Covenant was not, as to know what it was. Right now, let us look at three absolute proofs that the covenant which disappeared was not the Ten Commandments.
First of all, we notice that the Old Covenant had some poor promises in it. The New Covenant, we are told, "was established upon better promises." Hebrews 8:6. Tell me DHC, can you tell me if anyone, or even yourself, can point out any promise in the Ten Commandments that is poor? On the contrary, Paul declares that they were very good. "Children, obey your parents in the Lord: for this is right. Honour thy father and mother; which is the first commandment with promise; That it may be well with thee, and thou mayest live long on the earth." Ephesians 6:1-3.
The above text alone is sufficient to prove that the writer of Hebrews was not charging the moral law with any weak promises. The Old Covenant, the one that was abolished, whatever else it might be, could never be the Ten Commandments.
The second thing wrong with the Old Covenant was that it was faulty. The Bible says, "For if that first covenant had been faultless, then should no place have been sought for the second." Hebrews 8:7. Let me ask you another question DHC. Can you, or can you refer me to anyone else, who can find anything faulty in regards to the personal handwritten law of God? The psalmist declared, "The law of the Lord is perfect, converting the soul." Psalm 19:7. Paul wrote, "Wherefore the law is holy, and the commandment holy, and just, and good." Romans 7:12.
If King David, a man after God's own heart, and the apostle Paul, the greatest missionary who has ever lived, could agree that God's law is perfect, holy, just, and good, then what on earth is the modern theologian on about when he claims it is faulty?
Finally DHC, we have the clincher, after which any reasonable student of the Bible, or for that matter the English language, could ever again claim that the Ten Commandments have been abolished, or that they alone comprised the old covenant. Here is the most dramatic thing about the Old Covenant - it was to be abolished! "In that he saith, A new covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away." Hebrews 8:13. Now we can ask a serious question that should settle every doubt on this matter.
Did the great moral law of Ten Commandments vanish away?
Anyone DHC, including yourself, who has read the New Testament must answer, Absolutely not. Paul affirms the exact opposite about the law. He asked, "Do we then make void the law through faith? God forbid: yea, we establish the law." Romans 3:31.
Does the Bible contradict itself?
Can something vanish away and be established at the same time?
Did the same writer say opposite things about the same law?
Just to be certain that Paul was not saying that the Old Covenant was the law, let us insert the words "Old Covenant" instead of the word "law" into Romans 3:31. "Do we than make void the Old Covenant through faith? God forbid: yea, we establish the Old Covenant." Your entire premise above DHC in your post above, would have us believe that Romans 3:31 means precisely this. That the old covenant is vanished away, and established all at the same time!
That doesn't sound right at all, does it? We know that the Old Covenant has vanished away, for the writer of Hebrews is adamant on that. Yet it can hardly be credible of such a learned man as Paul, under the inspiration of the Spirit, could in another letter claim the precise opposite! Very clearly, then, we can see that the covenant which came to an end could not have been the Ten Commandments.
Because your post was written in response to the Sabbath question, I would like to now turn to that. Let us first establish a couple of theological statements upon which you and I will agree.
First, the new covenant, as with the old, was ratified by blood. Yes? See Exodus 24:4-8; and Hebrews 13:20,21.
Next point we would agree on DHC would be the truth that once ratified, no testament may be altered. See Hebrews 9:16,17 and Gal. 3:15.
Thus DHC anything added subsequent to Calvary, or taken away subsequent to Calvary, cannot have any part in the new covenant. Correct? For example, Jesus shared the passover supper with His disciples prior to His death, making the "Lord's Supper" an ongoing memorial for His church to commemorate until He comes again. This needed to be done prior to Calvary, because afterwards would have been too late, and couldn't be included in any new covenant.
So the question arises, when was Sunday- keeping introduced? And if the Sabbath was abolished as you claim, when was this done? For it had to be accomplished prior to Christ's death in order to be an established point of truth in the New Covenant, and it had to be accomplished by an equally powerful and divinely proclaimed pronouncement as it was introduced. If Jesus intended that the Sabbath was to pass away, then one would think that the Thursday night in that supper room would have been the perfect opportunity, seeing how He was about the business of adding a last minute clause to the new covenant. But no, not any intimation whatsoever that such an important change had taken place. Not even the slightest of hints.
Even resurrection day was 3 days too late!!!