An additional reason there is no mixing or confusion of law and gospel in Kline’s republication paradigm is because of his clear distinction between the underlying layer (the covenant of grace, by which the elect obtain the eternal inheritance) and the upper typological layer (the typological covenant of works governing Israel’s retention of the earthly, typological inheritance). The authors of MM simply gloss over the massive structural distinction between the type and the antitype, between long life in the land of Canaan and eternal life in heaven. If Kline did not make that distinction between the two layers, then he would indeed be guilty of mixing law and grace in the same covenant as the authors of MM charge. But because Kline clearly distinguishes the two layers, and sees them as governed by antithetical principles of inheritance (works governing Israel’s retention of the typological inheritance, grace governing the elect’s obtaining of the eternal inheritance) there is no mixing or confusion of works and grace in the Klinean paradigm:
Paul, perceiving the works principle in the Mosaic law economy, was able to insist that this did not entail an abrogation of the promises of grace given to Abraham, Isaac, and Jacob centuries earlier (Gal 3:17), precisely because the works principle applied only to the typological kingdom in Canaan and not to the inheritance of the eternal kingdom-city promised to Abraham as a gift of grace and at last to be received by Abraham and all his seed, Jew and Gentile, through faith in Christ Jesus (KP 237).
Samuel Bolton (an invited commissioner to the Westminster Assembly) made a similar distinction:
[The subservient covenant made with Israel at Sinai] was temporary, and had respect to Canaan and God’s blessing there, if and as Israel obeyed. It had no relation to heaven, for that was promised by another covenant which God made before He entered upon the subservient covenant ... though under these temporal blessings spiritual blessings were shadowed and apprehended by those who were spiritual (The True Bounds of Christian Freedom, Puritan Paperbacks, 99, 113-14).
So the concern of the authors of MM that, on the Klinean paradigm, “grace and works have been combined as opposing principles in a single covenant in a ‘tug of war’ kind of tension with one another” is shown to be unfounded. There is no “instability” or “tug of war” or “confusion” between grace and works, since they apply to different layers (the typological layer vs. the underlying soteriological reality) and since the one was added by way of subserviency to the other—as Paul himself so clearly taught in Galatians.
On the surface the authors of MM appear to be fighting against Kline, charging his republication paradigm with instability. But in reality they are fighting against Paul himself. Does Kline reintroduce the covenant of works in some form after the Fall? So does Paul. “The law came in to increase the trespass” (Rom 5:20). Does Kline think there is some way in which the antithetical principles of works and grace can coexist without annulling the promise? So does Paul. “The law ... does not annul a covenant previously ratified by God, so as to make the promise void” (Gal 3:17). Does Kline see two layers—an underlying layer of grace that continues on into its fulfillment in Christ, and a temporary superadded layer governed by law? So does Paul. “The law was added ... until the Seed should come” (Gal 3:19). If Kline’s thought is plagued by dangerous “instability,” then so is Paul’s.