"The view that strikes the language of 'merit' from our theological vocabulary so that the claim is made that Christ’s merits are not imputed to his people is contrary to the Westminster Standards."The argument of the proponents of the Federal Vision is that man, by virtue of his creatureliness, cannot merit anything from his Creator or bring the Almighty into his debt. This has ramifications not only for the covenant of works (since God only deals with his creatures graciously), but also for the view that Christ's obedience and satisfaction earned our eternal inheritance. The Father, they argue, graciously bestowed the reward upon his Son.
To the Standards, shall we?
The "everlasting inheritance" that our Lord has gained for us is something that he "purchased" (WCF VIII.5), the purchase price being his "perfect obedience and sacrifice" (WCF VIII.5). The payment of this price "fully satisfied the justice of the Father" (WCF VIII.5). Moreover, the saints' perseverance in the faith is attributed to "the efficacy of the merit and intercession of Christ," his intercession being grounded in "the merit of his obedience and sacrifice on earth" (WCF XVII.2; WLC 55). Finally, worthy participation in the Lord’s Supper includes our "trusting in [Christ's] merits" (WLC 174).
In his devastating critique of the covenant theology of the Federal Vision, Michael Horton cites Calvin:
"By his obedience, Christ truly acquired and merited grace for us with the Father.... I take it to be a commonplace that if Christ made satisfaction for our sins, if he paid the penalty owed by us, if he appeased God by his obedience... then he acquired salvation for us by his righteousness, which is tantamount to deserving it.... Hence it is absurd to set Christ's merit against God's mercy" (Covenant, Justification, and Pastoral Ministry, 206-07; Calvin, Institutes of the Christian Religion, 2.17.3, 1).Though there is no law, external to God, by which man can bring the Almighty into his debt, Adam would have had a claim upon the promised blessings of the covenant of works had he obeyed the stipulated terms of that covenant. Moreover, our Lord Jesus Christ, as second Adam, is able to claim those blessings (and more) on behalf of his people, grounding his claim on the Father’s promise to impute the benefits of his obedience and sacrifice to his elect. Thus, there is more to Jesus' work than "an inherent worth" (as the Federal Visionists call it); it is the means by which he earned for sinners what they could never merit on their own.