From the pen of Dr. Sam Waldron:
… for Pratt the present fulfillment of the New Covenant is merely anticipatory of its real fulfillment in the eternal state. This must be the case, because, for Pratt, none of its provisions are strictly fulfilled until the eternal state. In fact, in the respects that make the New Covenant new, it is according to Pratt’s own statements akin to all the previous Divine covenants including the Mosaic Covenant.
Now surely on the face of it this is a surprising conclusion for Pratt to draw. Though the NT teaches that there is both a present (inaugural) and future (consummate) fulfillment of the New Covenant, Pratt wants to reserve all of its distinctively new elements to the consummate state and deny them all to the inaugural state.
What makes this conclusion even more unconvincing is that the NT makes clear repeatedly that the New Covenant has already been legally established or enacted. This is shown by the fact that its ordinances have been legally established (Lk. 22:20; 1 Cor. 11:25) and its officers have been legally installed (Eph. 2:20; 4:11; Heb. 8:1–6; 2 Cor. 3:6). It is also shown by the language of Heb. 8:6 which, using the terminology of legal institution, says that it “has been enacted on better promises.” James R. White speaks very pointedly to this issue:
“It is important to see that for the writer, the New Covenant has been, as a past-tense action, officially enacted. The term used is νενομοθέτηται, the perfect passive of νομοθετέομαι, “to enact on the basis of legal sanction, ordain, found by law” (BDAG). The New Covenant is not something that will someday be established but has already, as a completed action, been founded, established, enacted, and that upon “better promises” than “the first” (v. 6). There is nothing in the text that would lead us to believe that the full establishment of this covenant is yet future, for such would destroy the present apologetic concern of the author; likewise, he will complete his citation of Jer. 31 by asserting the obsolete nature of the first covenant, which leaves one to have to theorize, without textual basis, about some kind of intermediate covenantal state if one does not accept the full establishment of the New Covenant as seen in the term νενομοθέτηται”.
Finally, the present (real) enactment of the New Covenant is indicated by the fact that Jesus cites one of the passages that most explicitly speaks of the consummate state as already in the process of fulfillment. Jn. 6:45 says, “It is written in the prophets, ‘AND THEY SHALL ALL BE TAUGHT OF GOD.’ Everyone who has heard and learned from the Father, comes to Me.” Plainly, Jesus regards this prophecy as already being fulfilled during His life and ministry. You will notice, furthermore, that the reference at the beginning of the verse is to the “prophets” (plural). The reason for this is that Jesus is combining two OT prophecies in the words He cites. Those two passages are Is. 54:13, which predicts “all your sons will be taught of the Lord,” and Jer. 31:34, which predicts, “they shall all know Me.” Thus, Jesus assumes that there is a present fulfillment of this passage as well as a future. The New Covenant is inaugurated in this age and consummated in the age to come.
For all these reasons, Pratt’s conclusion strikes one as a surprisingly extreme and likely biased deduction from the consummate fulfillment of the New Covenant. A more natural conclusion is that the New Covenant (de jure) now forms the legal constitution of the church, even though its actual condition still resembles in some respects (de facto) the condition of the people of God under previous covenants.
This is the more natural explanation for a number of the passages Pratt cites in order to prove that the present people of the New Covenant is composed of both believers and unbelievers. In spite of the new legal situation that obtains through the enactment of the New Covenant, the merely inaugural fulfillment of the New Covenant means that the actual condition of the church sometimes, and to some degree, resembles that of the mixed multitude of Israel. This is the explanation for Heb. 10:29 and other passages in the NT.
Pratt exemplifies how Heb. 10:29 is cited frequently by paedobaptists today. A few comments about the meaning of this passage are appropriate. The apostasy passages of Hebrews are plainly speaking only of those who actually professed regeneration – not of infants supposedly born or baptized into the New Covenant. Those mentioned in Heb. 10:29–30 are the same as those mentioned in Heb. 2:3–4 and 6:4–6, where their conversion experiences are described. This is plain in Jn. 15:1–6. Notice the contextual reference to Judas Iscariot (Jn. 13:10, 11, 30). This is plain also in Rom. 11:16–24 from the fact that it is faith that grafts people into the one olive tree.
The paedobaptist use of the apostasy passages is caught on the horns of a dilemma. If they admit that the apostates are described in these passages as “sanctified” and “in Christ” because of what they professed and claimed, then it must take the position that infants may be admitted to the New Covenant only on the supposition that they are regenerate. Unless they adopt the doctrine of the presumptive regeneration of their infants, this lands them in the Baptist position of baptizing only those who profess regeneration. Since presumptive regeneration assumes that it is unnecessary to evangelize our children, is devoid of biblical support, and involves difficult logical gymnastics, most Evangelical paedobaptists hesitate to take this ground for baptizing their infants.
But the other horn of the dilemma for paedobaptists is to argue that the language of “sanctified” and “in Christ” as used in the apostasy passages has nothing to do with the profession of regeneration. These paedobaptists argue that it merely speaks of some “covenantal” blessing really possessed by the apostates, but makes no reference to regeneration. The problems with this approach are manifold. In the first place, it must attribute two completely different meanings to the same words used in the same chapters. For instance, in Heb. 10 “sanctified” must mean something completely different in vv. 10 and 14 than it does in v. 29. It must also invent a merely covenantal and non-saving meaning for “in Christ” in Jn. 15 and “by faith” in Rom. 11.
But in the second place, since paedobaptists argue that this merely covenantal (but non-saving) connection to Christ is given to people through their participation in the ordinances of the New Covenant (through baptism and the Lord’s Supper), they must change the meaning of baptism and the Lord’s Supper. Now baptism and the Lord’s Supper do not claim or profess or signify repentance and the forgiveness of sin, but only some non-saving covenantal connection to Christ. The problem, of course, with this position is that it defies the plain teaching of the entire NT about the meaning of the ordinances.
A more satisfactory interpretation of the apostasy passages argues that in them the language of profession or appearance is used. Those mentioned in the apostasy passages are described according to their external and visible profession and privileges, not according to inward and spiritual reality (1 Cor. 8:11; Rom. 14:15). If these passages imply that a brother can perish, such a one is described only as to his visible profession. For a true brother cannot perish (Rom. 14:4). Heb. 10:29 speaks of one sanctified by the blood of Christ. Those who are truly sanctified, however, have been perfected forever through Christ’s death (Heb. 10:10, 14), and enjoy the blessings of the New Covenant (Heb. 10:15–18). Those mentioned in Heb. 10:29 are only sanctified, therefore, in terms of the language of the profession and appearance, and not in reality.*
* Vol. 2: The Reformed Baptist Theological Review Volume 2. 2005 (1) (106–109). Owensboro, KY: Reformed Baptist Theological Review.