The Function of Faith in Justification
The following article appears in Volume II, page 437 of Pieper’s Christian Dogmatics. Pieper explains why the correct translation is justification “by faith” or “through faith” and not “because of faith.”
5 The Function of Faith in Justification: In the preceding characterization of faith we have stated again and again that justifying faith must be viewed merely as the instrument, or the receptive organ (medium lepticon), for apprehending the forgiveness of sins offered in the Gospel. But the many errors which have arisen in the Church on this point call for a special section in which the instrumental character of faith is more fully set forth.
On this score, especially the clear teaching of Scripture has been rendered obscure. The Biblical terms ‘by faith’ and ‘through faith’ have been given an entirely unscriptural content. It must be stressed that no intrinsic value dares be ascribed to justifying faith in addition to the grace of God in Christ. This is precisely the meaning of the statement that faith is merely the instrument of receiving the grace of God; and that is exactly what Scripture teaches. In treating of justification Scripture places faith in opposition to all works and all goodness in man. ‘By faith, without the deeds of the Law’ (Rom. 4:5). The Lutheran Confessions declare again and again: ‘The sole office and property of faith is that it is the means or instrument by and through which God’s grace and the merit of Christ in the promise of the Gospel are received, apprehended, accepted, applied to us, and appropriated’ (Trigl. 929, F. C., Sol. Decl., III, 38). ‘Faith justifies and saves, not on the ground that it is a work in itself worthy, but only because it receives the promised mercy’ (Apol., Art. IV [II], 56; 147, ibid., 86; Trigl. 919, F. C., Sol. Decl., III, 13).
That is also the meaning of the Lutheran axioms: ‘Faith justifies not in the category of quality, but in the category of relation’; ‘Faith justifies not as an act by itself, but because of the object which it grasps’; ‘Faith justifies not as a work, but as an instrument.’