Christ is the end of the law
Few tenets single-handedly characterize New Covenant Theology, but its rejection of the "third use of the law" comes pretty close. Reformed theology, historically, has postulated that there are three uses of the law: 1. Use of the law to convict men of sin, 2. Use of the law to restrain evil, and 3. Use of the law as the biblical (and eternal) standard for Christian behavior. These three "uses" can be found not only in many of the classic Reformed documents, interestingly enough it also can be found in the Lutheran "Book of Concord." While affirmation of the first two uses is widely varied within the New Covenant Theology community, the movement universally has rejected the third use as unbiblical (on various grounds, which are not the subject of this post).
Closely related to threefold use of the law is the theological argument that underlies and gives rise to the threefold use of the law: the threefold categorical distinction of the law which divides the law into ceremonial, civil and moral categories. While these categories may be helpful in helping understand the role of law in Old Testament Israel, these categories are unhelpful when it comes to rightly understanding various biblical authors' views of the law in the New Testament.
Per the division of the law into three categories, NCT pastor and theologian Blake White has written, "Although this tripartite distinction is historically rooted and held by many men more respectable and learned than the present writer, it must be rejected. this distinction simply will not hold up to exegesis. It is a theological construction imposed on the Text of Scripture. For Paul to accept circumcision is to obligate oneself to keep the whole law (Gal. 5:3). for James, to fail in one point of the law is to become accountable for all of it (Ja. 2:10). Everything God demanded from Israel was moral. The law is a unit." -- Blake White, "The Law of Christ: A Theological Proposal", pp. 56-57
Lest one think that it is a characteristic unique to New Covenant Theology to deny the exegetical value of dividing the law into ceremonial, civil, and moral categories, there are many others who have raised similar objections. Theologians such as Douglas Moo point out that the law in the New Testament is treated as a unit. In fact, Moo points out that "95 percent of the time" when the NT writers are using the word for "Law" they are talking about "the Mosaic Law". This means that although there are some distinctions in the way the term "law" is used, those distinctions are unified under "the Mosaic Law" umbrella. Further, as to whether it's possible to make a case for three categories of law, Moo says that "the Christian must always view the *whole* law only under the condition of its fulfillment. No commandment, even those of the Decalogue, is binding simply because it is part of the Mosaic Law...the NT does not approach the matter this way. The *whole law*, every 'jot and tittle', is fulfilled in Christ and can only be understood and applied in light of that fulfillment." -- Douglas Moo, "The Law of Moses or the Law of Christ?" in "Continuity and Discontinuity: Perspectives on the Relationship Between the Old and New Testaments", ed. John Feinberg, pp. 217-218
Tom Schreiner also believes one cannot exegetically make the case that the New Testament writers held to the tripartite view espoused by many in the Reformed camp: "Neither Paul nor any other New Testament writer explains the role of the law by appealing to (moral, ceremonial, and civil) categories. Instead, Paul argues that the law is both abolished and fulfilled in Christ." -- Thomas Schreiner, 40 questions about Christians and Biblical Law, p. 94
Jason Meyer agrees, saying "the NT itself does not make these three distinctions, and no one living under the law of Moses seriously thought they could pick which parts were binding and which were optional. God's law comes as a set with no substitutions. Therefore, exegetes should not read the three distinctions into NT texts that speak of the law as a singular entity. Furthermore, one will find it challenging to divide all the laws into three neat, watertight compartments." Jason C. Meyer, "The End of the Law: Mosaic Covenant in Pauline Theology", p. 282.
Stephen Westerholm is another case in point: "...the objection is frequently raised that, while Paul does not believe the Christian is obligated to observe the Old Testament ceremonial law, he does believe the Christian is obligated to observe its moral commands. Such distinctions are the inevitable result of the view that the law still states the binding requirements of God for the Christian, since no one imagines that Paul thought Christians were obligated to observe its statues of circumcision or ritual purity. Were it true, however, that Paul considered the law or any part of it still binding for the Christian, he would have had to provide his churches with detailed instructions as to which command they were obligated to observe and which they were not: this would obviously be a very important matter! But there is no evidence that he made any such distinctions. On the contrary it is clear that, for Paul, Torah was a unit. On this point he did not differ from the standard Jewish view: the person who is obligated to observe the law is obligated to observe its every precept. That, for Paul, is true of the person who is under the law (cf. Gal. 5:3); it is not true of the Christian." -- Stephen Westerholm, Israel's Law and the Church's Faith: Paul and His Recent Interpreters, pp. 207-208
Westerholm goes on to point out that even though Paul is quick to point out the inadequacy of "all things are lawful" (1 Cor. 6:12, 10:23) as a guideline for Christian behavior, it's amazing he even made the statement at all. "Both the slogan itself and Paul's non-legal way of qualifying it clearly indicate that the Christian is not thought to be obligated to observe the demands of the law. The law, after all, forbids as well as commands; of no one subject to its demands can it be said that everything is 'lawful.' What makes Paul's refusal to reject the slogan 'All things are lawful' even more astonishing is the contexts in which it is raised: discussions of fornication with prostitutes (1 Cor. 6:12-20), and of the propriety of eating food offered to idols (chs. 8,10). Surely if Paul was ever to 'lay down the law,' if Torah was to be invoked in any sphere as the standard for Christian behavior, then the subjects of sexual morality and commerce with idolatry presented him with opportunities without equal. But Paul declined the temptation." -- Stephen Westerholm, Israel's Law and the Church's Faith: Paul and His Recent Interpreters, p. 208
It's interesting that Westerholm raises this last point. That very argument comes into play in Paul's second (or is it third? But I digress) letter to the Corinthians. By the time that letter is written, the church in Corinth has a problem with good old fashioned Judaizers. Whodda thunk, with this predominantly Gentile congregation, that service to the law would be a problem? But that problem is what Paul is addressing toward the end of chapter two and with all of chapter three. How does Judaism take hold in a place like that? Because the church had a morality problem. What better way to fix the morality problem than to introduce the law into the church? What better way to contravene Paul's "all things are lawful" than by introducing the law? The problem with the church at Corinth is that Paul had given them too much freedom. They needed more law. They needed someone "peddling" the moral demands of the law.
But that law, for Paul, is obsolete, having been "brought to an end" (2 Cor. 3:11). The Corinthians don't need more law. What they need is "the light of the gospel of the glory of Christ." (2 Cor. 4:4). Transformation doesn't come through obeying the moral demands of the law. Transformation into the image of Jesus comes through "beholding" the "unveiled face" of Jesus Christ (2 Cor. 3:18). This is why Paul's proclamation to the Corinthian church is not himself (implying that preaching himself would be the Old Covenant, faded-glory thing to do as his Judaizing opponents were doing), but "Jesus Christ as Lord" (2 Cor. 4:5) and it is through that life-giving and life-sustaining Proclamation of Jesus that God has shone into the heart of the church "to give the light of the knowledge of the glory of God in the face of Jesus Christ".
What does this mean for the Christian? While answering this is beyond the scope of this present post, it can at least be said, via Westerholm that the relationship with the law is "in the past... believers have been redeemed (Gal. 4:5) or 'set free' (Rom. 7:6) from the law... they have died to the law (Rom. 7:4, 6, cf. Gal. 2:19) The upshot is that they are not 'under law' (Rom. 6:14-15; cf. 1 Cor. 9:20). Christ has brought an end to the law. The entire law. Christ fuliflled the law, filling up the Law's meaning to its fullest and highest extent so that we would be free from its tyranny.
Moo points out that "when the 'antinomian' implications of Paul's teaching were raised as an objection against that teaching, Paul responded not by introducing a 'new law' but by pointing to the Spirit (Gal. 5:16ff) and to union with Christ (Romans 6)...any approach that substitutes external commands for the Spirit as the basic norm for Christian living runs into serious difficulties with Paul." -- Douglas Moo, "The Law of Moses or the Law of Christ?" in "Continuity and Discontinuity: Perspectives on the Relationship Between the Old and New Testaments", ed. John Feinberg, pp. 217-218
Such is the nature of Christ's fulfillment of the Mosaic Law (and indeed the Old Testament) in redemptive history. As the goal of the law, Christ is its intended end. Christ is its terminal point. Christ is everything the law foreshadowed. Christ is the full and final expression of the eternal character of God. And this has many implications for understanding law as a category in the New Covenant. As Jason Meyer says, "The coming of Christ has caused a paradigm shift that calls for recalibrating all former commands in the light of His centrality." -- "The End of the Law: Mosaic Covenant in Pauline Theology", p. 283.