The proper distinction between the Law and the Gospel is set aside and hence Law and Gospel are commingled by -
a. The Romanists, who mingle the Law and the Gospel in the interest of their pernicious teaching of work-righteousness and of the uncertainty of salvation. The Council of Trent expressly anathematizes the doctrine that the "Gospel is the absolute and unconditional promise of eternal life, without the condition that he (man) must first keep the Law" (Seas. VI, Can. 20).
b. The Calvinists, who deny the gratia universalis and the operation of the Holy Ghost through the divinely appointed means of grace. In consequence of these errors they do not proclaim the universal Gospel promises of grace to all sinners, but condition the sinner's salvation on his compliance with the prescribed conditions on which God will accept the sinner. According to Charles Hodge the "external call" is "a promise of acceptance in the case of all those who comply with the conditions," while the Gospel is "a proclamation of the terms on which God is willing to save sinners and an exhibition of the duty of fallen men in relation to that plan" (Syst. Theol., II, 642). Thus, in the final analysis, the Calvinists commit the same fatal mistake as the Romanists.
c. The synergists, who deny the sola gratia and make salvation depend on the sinner's own decision for grace. According to synergism the Gospel is a message of God promising grace to all who will apply themselves to grace. Synergism is therefore a return to the Pelagianistic camp of Romanism.
d. All Modernists, who deny the satisfactio vicaria; for, since they deny the vicarious atonement of Christ, they must teach salvation by works or the sinner's own atonement for his sins.
e. Certain modern theologians, who affirm a "higher unity" ("hoehere Einheit") between the Law and the Gospel. According to their opinion the difference between the Law and the Gospel is one only of degree, not one of kind; for both, as it is falsely claimed, demand of the sinner moral works. In that case the Gospel, in the final analysis, is only a modified Law. This erroneous view, of course, completely annuls the distinction between the two doctrines. It converts the Gospel into Law and makes the sinner's salvation depend on his own obedience.
Luther, who is represented by these errorists as favoring this pernicious opinion, in reality distinguished between the Law and the Gospel as plus quam contradictoria.
In closing this chapter, we may call attention to the fact that in all cases where the Law and the Gospel are mingled into each other the purpose is always the same, namely, to eliminate the "foolish preaching'' of the crucified and risen Savior as man's only hope of salvation and to confirm the pagan doctrine of salvation by works (opinio legis).
The result of all error in theology is, in the final analysis, the elimination of "the Lamb of God, which taketh away the sin of the world," John 1, 29. Luther says very correctly (St. L., XX, 873): "Whoever denies, blasphemes, or dishonors Christ in one point or article can teach or honor Him rightly in no other place."
In a more subtle way the Law and the Gospel are commingled by all who weaken the rigor of the Law, teaching that God is satisfied if men obey it as much as they can; by all who inject legal elements into the Gospel, depriving it of its sweetness; and by all who proclaim the Law to terrified sinners and the Gospel to such as are secure and carnally indifferent. The Law and the Gospel may thus be commingled with respect to their nature and contents, with respect to their functions, and with respect to the persons dealt with. But whenever the Law and the Gospel are commingled, the doctrine of justification by grace and the certainty of salvation are destroyed. In fact, where the distinction between the Law and the Gospel is not known and practised, there no man can become or remain a Christian. Luther's words therefore deserve careful consideration: "This distinction between Law and Gospel is the supreme art in Christianity, which all who glory in, and bear, the Christian name may and should understand." (St. L., IX, 798.)