The saving power of faith resides thus not in itself, but in the Almighty Saviour on whom it rests. It is never on account of its formal nature as a psychic act that faith is conceived in Scripture to be saving,—as if this frame of mind or attitude of heart were itself a virtue with claims on God for reward, or at least especially pleasing to Him (either in its nature or as an act of obedience) and thus predisposing Him to favour, or as if it brought the soul into an attitude of receptivity or of sympathy with God, or opened a channel of communication from Him. It is not faith that saves, but faith in Jesus Christ: faith in any other saviour, or in this or that philosophy or human conceit (Col. 2:16, 18, 1 Tim. 4:1), or in any other gospel than that of Jesus Christ and Him as crucified (Gal. 1:8, 9), brings not salvation but a curse. It is not, strictly speaking, even faith in Christ that saves, but Christ that saves through faith. The saving power resides exclusively, not in the act of faith or the attitude of faith or the nature of faith, but in the object of faith; and in this the whole biblical representation centres, so that we could not more radically misconceive it than by transferring to faith even the smallest fraction of that saving energy which is attributed in the Scriptures solely to Christ Himself.
Biblical Doctrines, vol. 2 of The Works of Benjamin B. Warfield (New York: Oxford University Press, 1932; repr., Grand Rapids: Baker, 2000), 504.