Reader R.B. had two interesting questions regarding our suzerain covenant series:
1. Under what conditions could any of these covenants be terminated, even if some of the people wanted it to continue? (Obviously, I'm thinking of the Mosaic Covenant here.)
2. Under what conditions could a new covenant replace or supercede an existing covenant? Even more obviously, I'm thinking of the Christian Covenant superceding the Mosaic Covenant. If it doesn't, then it would seem that a person of Jewish descent who chooses to follow Christ is bound to, at a minimum, the Mosaic and Christian covenants.
Let us discuss each in turn, as I think these are great questions to fulfill our study on suzerain covenant theology in Scripture.
We will answer these questions first in general (applying to all covenants), then specifically (regarding the relationship between the covenant of Moses and the covenant of the Christ.
Recall that a suzerain covenant is a covenant enacted between a sovereign (in this case, God), and a vassal. The suzerain offers his protection in return for certain behavioral agreements of the vassals. If the vassal upholds his end of the covenant, the sovereign provides certain blessings; if the vassal does not, then certain curses are given to him.
Now what will end a covenant? Well, if the covenant is time-based, it certainly ends at the conclusion of the time period (though this is somewhat rare). Far more often, the covenant's continuing validity always comes into question when the head of state of the sovereign or vassal changes; thus, covenants are frequently renewed when the parties change. Another instance in which a covenant can go "bad" is failure of the vassal to uphold his end of the deal. However, if one of these events does not happen, a covenant will not be broken - the covenant is valid until either the conditions and terms are broken or some extraordinary other event (change in headship of the sovereign, for example) causes it to be cancelled.
Once a covenant is cancelled, it is up to the sovereign how to continue. He may renew the covenant, replace it with a different covenant, or cease the covenant relationship completely.
Now, more directly to R.B.'s questions, we come to the specifics: is the Mosaic Covenant still in effect for those born of Jewish descent, or was it replaced by Jesus and the Christian Covenant?
A few points need to be made here.
1. The Christian Covenant is not a candidate for replacement of the Mosaic Covenant.
If we stipulate that the Jews were unable to uphold their end of the bargain in the Mosaic Covenant, then God has the right to cancel or renegotiate the covenant. However, this is not what happened with the Christian Covenant. You see, any replacement covenant must be with the same people (Jewish nation only) and the same end goal in mind (God's protection of the Jewish earthly kingdom).
Because the New Covenant does not deal with Jews exclusively, or with Jewish nationalism at all, then it cannot be a candidate for replacement of the Mosaic Covenant. At most, it can be an overlapping addition to the Mosaic Covenant, but never a replacement.
2. Jesus Himself said that the Mosaic Covenant would not pass away.
In Matthew 5:18, during His Sermon on the Mount, Jesus stated that the Mosaic Covenant would not pass away until the end of the the earth. In fact, most Christians misunderstand the Sermon on the Mount. Though it is a great ethical dialogue and very relevant for Christian theology, it is properly understood as a commentary on the existing Mosaic Covenant, not on the New Covenant (which had not yet been instituted!).
3. Peter was appalled at the thought of violating the Mosaic Covenant in order to minister to Gentiles.
In Acts 10:9-48, in a dream, Peter is commanded by God to minister to a Gentile and, in the process, violate the Mosaic Covenant food laws. Peter is apalled by the thought, as clearly he believed that he was held to the Mosaic Covenant.
Many Christians read this passage as God telling Peter that it is okay to violate the Mosaic Covenant, despite his Judaism. However, that is not ever stated! Rather, God simply states that there is nothing inherently corrupt about the food, and that He is allowing Peter to violate his Mosaic commitments when ministering to Gentiles. Later we see that Peter maintains commitment to the Mosaic Covenant any time that he is not directly ministering to Gentiles (Gal 2:11), even to the point of misleading them with his inconsistent behavior (and, therefore, calling down the wrath of Paul).
Clearly, Peter felt that God allowed him to violate his Mosaic commitments in order to minister to the Gentiles, but did not feel that he was freed from the commitment altogether (hence his eating properly when not around Gentiles).
4. The Council of Jerusalem clearly understood the Mosaic Covenant to still be active.
In Acts 15:1-21, Christian apostles and bishops from around the Near East gathered in Jerusalem, and held the first ever ecuminical council of Christianity. The topic was to discuss whether Gentiles had to uphold the Mosiac Covenant (v. 5-6).
James, the bishop of the church of Jerusalem, was the leader of the council. In verses 13-21, he issued the ruling of the Council: Gentiles were not held to the Mosaic Covenant, and their only requirements in addition to the New Covenant were abstaining from consumption of blood, abstaining from idolatry, and abstaining from sexual immorality.
Now what does this mean in covenantal terms? The Council has freed the Gentiles from any requirement spelled out in the Mosaic Covenant. Avoidance of idolatry and sexual immorality are clear from the teachings of Jesus, and therefore a part of basic Christian behavior. The other requirement (abstinance from blood consumption) simply restates the Noahic Covenant, to which all men are bound.
Implicit within this discussion, however, is a key fact: Jewish Christians were not given the same liberty. Clearly, the Council believes that the Mosaic Covenant still applied to Jews, and only spoke of freedom from this Covenant when talking to Gentiles.
Answer (Pt 1)
Based upon the above information, we can answer R.B.'s questions.
Suzerain covenants can be cancelled or renegotiated any time that the vassal has violated or a major change has occurred. So yes, in theory, God could have sent a New Covenant that abolished the Mosaic Covenant ("the Law").
However, that is not what happened. Jesus did not teach a New Covenant for earthly protection of the Jews; His Covenant deals with eternal protection of all people, and thus is not a replacement of the Mosaic. Furthermore, Jesus explicitly stated in the Sermon on the Mount that He was not abolishing the Mosaic Covenant, and further spent the majority of His ministry teaching Jews how to better uphold this covenant. Peter was initially appalled at the thought of setting aside his Jewish requirements temporarily in order to minister to a Gentile. Finally, the Council of Jerusalem indicated that Gentile Christians were excepted from the requirements of the Mosaic Covenant, clearly assuming that the Jews were not.
Based on all of this, one could still argue that Jews were still held to the Mosaic Covenant today: that if Jews were capable of upholding the covenant, God would uphold His end and make Israel a powerful nation, a holy priesthood, once again.
Answer (Pt 2)
You would be wrong. :-)
You see, all of the above I said is true. But you forget that Jesus made a very specific prophesy. As I wrote about here, Jesus prophesied that the end of the Mosaic Era would come when the Temple was destroyed. The entire Mosaic Law is built upon a concept of sacrifice for forgiveness. Jesus replaces that sacrifice and offers grace once and for all, to all mankind.
Now when the Council of Jerusalem was written above, the Temple was still operational. But as Jesus prophesied in Matt 24/Mark 13, the Temple would be thrown down in 70 AD during the Jewish-Roman War. At the conclusion of this time, the Mosaic Law and Israel's role as God's kingdom was destroyed. It was, truly, the apocalypse for the Jewish people.
From that moment on, it of course became clear to all Christians that God had, as was His right, cancelled the Mosaic Covenant once and for all. And in the nearly-2000 years since that date, there has been no Mosaic system of sacrifices as required. So when people today say that they wish to follow the Mosaic Law, keep in mind that they are not doing so--because there is no Temple for sacrifices.
So one could have a theoretical discussion about the period from Jesus' death (c.30 AD) and the Temple's destruction (70 AD) about whether Jewish Christians had to do both Judaism and Christianity. But that's all it is--a theoretical discussion. Because in 70 AD, God put a "close-parenthesis" on the Jewish Age. That day was over, and a New Covenant was all that existed.