In Reformed theology, there are different opinions as to whether or not or in what manner one can be a participant in the Covenant of Grace without being regenerate. The following article is a brief exposition of Berkhof's understanding of the different sorts of distinctions obtaining among various Reformed theologians as to what it means for an unregenerate person to in some sense be a participant in the Covenant of Grace.
1) Internal/external covenant - A person's covenant membership depends upon the performance of certain religious duties. Berkhof points out that such a criteria was operative in the Old Covenant within the context of theocratic membership. He cites the theologian Thomas Blake as a prime representative of this position. Some argue that one is an external partaker of the covenant body by virtue of one's profession of faith, others, with the Lord's supper, others yet, with respect to baptism. Berkhof ultimately rejects such a distinction. He rejects such a distinction on the grounds that it implies that one can be a part of the covenant without the salvific realities which inexorably attend it. Although he acknowledges the reality of 'external' privileges or blessings, such privileges and blessings do not themselves constitute a genuine covenant relationship.
2) Internal/external aspect of the covenant - it may confuse some to learn that Berkhof makes a distinction between an internal/external aspect of the covenant of grace.
Indeed, quite a few Presbyterians have historically held to such a position. Berkhof specifically cites Mastricht as an example. Such people accept "covenant responsibilities" merely with an external profession. He refers to Simon and Judas, whom he says are in the covenant externally by virtue of a purely temporal and non-internal faith. Berkhof ultimately rejects this distinction on the ground that it is only by other humans that such people are regarded as being genuine covenant partakers. They are not objectively in the covenant in the sight of God in any meaningful sense.
3) Essence/administration of the covenant - Berkhof cites Olevianus and Turretin who make a distinction between participating in the essence of the covenant vs. participating in the administration of the covennat. Those who participate in its essence are the true elect, whereas those who participate in merely the covenant's administration simply respond to the preached word and attend the visible ordinances of the church. The covenant's administration, Berkhof explains, simply refers to the "external privileges" shared by those who attend the visible church. This includes both elect and non-elect. He makes the point that a more legitimate antithesis would be essence/form rather than essence/administration, and rejects such an understanding of the dual aspect of the covenant. He argues that Turretin, by this distinction, has in mind the visible vs. invisible church, whereas Olevianus is referring to the "final end or realization" vs. "the announcement of the covenant." He ultimately rejects such distinctions because he does not believe that they can explain the manner in which non-elect members of the visible church are legitimate covenant-partakers in the sight of God.
4) Conditional/Absolute Covenant - Berkhof cites Koelman as an example of someone who distinguishes between between a conditional vs. an absolute covenant. He notes that Koelman's distinction is roughly equivalent to those who speak of an external/internal covenant or perhaps an internal/external aspect of the covenant.
5) Legal relationship/communion of life - Berkhof cites Geerhardus Vos as one who distinguishes between one aspect of the covenant as a communion of life on the one hand, and a legal relationship of the other. Vos understands the covenant as a kind of legal pact between two parties with legal stipulations and conditions. This legal element figures heavily into Vos' understanding of the how the covenant relationship is understood. From this perspective, Berkhof explains, members of the visible church are in the covenant even though they may not be regenerate, insofar as they are bound to satisfy the legal conditions of the covenant which they have taken on themselves. Regardless of whether or not one is regenerate or in real communion with God, one is legitimately part of the covenant membership from a purely legal condition. It is therefore the case, he concludes, that from this perspective, one can be in the Covenant of Grace from a purely legal perspective without truly participating in the communion of life as only regenerate church members do. Berkhof explicitly accepts such a position:
This distinction is warranted by Scripture. It is hardly necessary to cite passages proving that the covenant is an objective compact in the legal sphere, for it is perfectly evident that we have such a compact wherever two parties agree as in the presence of God to perform certain things affecting their mutual relation, or one party promises to bestow certain benefits on the other, provided the latter fulfills the conditions that are laid down. That the covenant of grace is such a compact is abundantly evident from Scripture. There is the condition of faith, Gen. 15:6, compared with Rom. 4:3 ff., 20 ff.; Hab. 2:4; Gal. 3:14-28; Heb. 11; and there is also the promise of spiritual and eternal blessings, Gen. 17:7; 12:3; Isa. 43:25; Ezek. 36:27; Rom. 4:5 ff.; Gal. 3:14,18. But it is also clear that the covenant in its full realization is something more than that, namely, a communion of life. This may be already symbolically expressed in the act of passing between the parts of the animals slain at the establishment of the covenant with Abraham, Gen. 15:9-17. Moreover, it is indicated in such passages as Ps. 25:14; Ps. 89:33,34; 103:17,18; Jer. 31:33,34 (Heb. 8:10-12); Ezek. 36:25-28; II Cor. 6:16; Rev. 21:2,3(Berkhof, "Systematic Theology").
He cites Ishmael and Esau, as well as the children of Eli, whom he believes were external partakers of the Covenant of Grace, yet were apostate, and therefore only participated in the Covenant of Grace in a legal sense, without entering into true communion of life with God. He cites Kuyper, whom he notes believed that they were "not essential" participants of the covenant, although they were genuinely in it, as well as Bavinck, who makes the distinction between "in foedere"(in the covenant) and "de foedere"(of the covenant). The former did apply to them, Bavinck argues, but the latter did not. Such unregenerate covenant partakers, Berkhof argues, are responsible to fulfil the legal obligations of the covenant, which he takes as their duty to repent and believe. Apart from such obedience, they are reckoned covenant breakers. Berkhof cites Rom. 9:4 in order to attempt to demonstrate this. For Berkhof, failure to enter into the covenant of life causes such a person to be reckoned a covennat breaker, on the grounds that they have not satisfied the legal stipulations of the covenant to repent and believe.