What does John Piper believe about dispensationalism, covenant theology, and new covenant theology?

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Covenant Theology
Covenant theology believes that God has structured his relationship with humanity by covenants rather than dispensations. For example, in Scripture we explicitly read of various covenants functioning as the major stages in redemptive history, such as the covenant with Abraham, the giving of the law, the covenant with David, and the new covenant. These post-fall covenants are not new tests of man's faithfulness to each new stage of revelation (as are the dispensations in dispensationalism), but are rather differing administrations of the single, overarching covenant of grace.

The covenant of grace is one of two fundamental covenants in covenant theology. It structures God's post-fall relationship to mankind; pre-fall, God structured His relationship by the covenant of works. The covenant of grace is best understood in relation to the covenant of works.

The covenant of works, instituted in the Garden of Eden, was the promise that perfect obedience would be rewarded with eternal life. Adam was created sinless but with the capability of falling into sin. Had he remained faithful in the time of temptation in the Garden (the "probationary period"), he would have been made incapable of sinning and secured in an eternal and unbreakable right standing with God.

But Adam sinned and broke the covenant, and thereby subjected himself and all his descendants to the penalty for covenant-breaking, condemnation. God in His mercy therefore instituted the "covenant of grace," which is the promise of redemption and eternal life to those who would believe in the (coming) redeemer. The requirement of perfect obedience for eternal life is not annulled by the covenant of grace, but is rather fulfilled by Christ on behalf of His people, since now that all are sinners no one can meet the condition of perfect obedience by his own performance. The covenant of grace, then, does not set aside the covenant of works but rather fulfills it.

As mentioned above, covenant theology emphasizes that there is only one covenant of grace, and that all of the various redemptive covenants that we read of in the Scripture are simply differing administrations of this one covenant. In support, it is pointed out that a covenant is in essence simply a sovereignly given promise (usually with stipulations), and since there is only one promise of salvation (namely, by grace through faith), it follows that there is therefore only one covenant of grace. All of the specific redemptive covenants we read of (the Abrahamic, Mosaic, etc.) are various and culminating expressions of the covenant of grace.

New Covenant Theology
New covenant theology typically does not hold to a covenant of works or one overarching covenant of grace (although they would still argue for only one way of salvation). The essential difference between New Covenant Theology (hereafter NCT) and Covenant Theology (CT), however, concerns the Mosaic Law. CT holds that the Mosaic Law can be divided into three groups of laws--those regulating the government of Israel (civil laws), ceremonial laws, and moral laws. The ceremonial law and civil law are no longer in force because the former was fulfilled in Christ and the latter only applied to Israel's theocracy, which is now defunct. But the moral law continues.

NCT argues that one cannot divide the law up in that way, as though part of the Mosaic Law can be abrogated while the rest remains in force. The Mosaic Law is a unity, they say, and so if part of it is canceled, all of it must be canceled. On top of this, they say that the New Testament clearly teaches that the Mosaic Law as a whole is superseded in Christ. It is, in other words, no longer our direct and immediate source of guidance. The Mosaic Law, as a law, is no longer binding on the believer.

Does this mean that believers are not bound by any divine law? No, because the Mosaic Law has been replaced by the law of Christ. NCT makes a distinction between the eternal moral law of God and the code in which God expresses that law to us. The Mosaic Law is an expression of God's eternal moral law as a particular code which also contains positive regulations pertinent to the code's particular temporal purpose, and therefore the cancellation of the Mosaic Law does not mean that the eternal moral law is itself canceled. Rather, upon canceling the Mosaic Law, God gave us a different expression of his eternal moral law--namely, the Law of Christ, consisting in the moral instructions of Christ's teaching and the New Testament. The key issue that NCT seeks to raise is: Where do we look to see the expression of God's eternal moral law today--do we look to Moses, or to Christ? NCT says we look to Christ.

There are many similarities between the Law of Christ and Mosaic Law, but that does not change the fact that the Mosaic Law has been canceled and that, therefore, we are not to look to it for direct guidance but rather to the New Testament. For example, England and the US have many similar laws (for example, murder is illegal in both countries). Nonetheless, the English are not under the laws of America, but of England. If an English citizen murders in England, he is held accountable for breaking England's law against murder, not America's law against murder.

The benefit of NCT, its advocates argue, is that it solves the difficulty of trying to figure out which of the Mosaic laws apply to us today. On their understanding, since the Mosaic Law is no longer a direct and immediate source of guidance, we look to the Law of Christ for our direct guidance. Although the Mosaic Law is no longer a binding law code in the NT era, it still has the authority, not of law, but of prophetic witness. As such, it fills out and explains certain concepts in both the old and new covenant law.