At the heart of the Reformation was the rediscovery by Luther and the Reformers of the doctrine of justification by grace alone, through faith alone in Christ alone. The doctrine of justification by faith gave a believer assurance of an end-time verdict made real now by faith, i.e. one did not have to wait until the end time as one appeared before the Lord to receive one’s final verdict.

Justification by faith meant that the perfect righteousness of Christ was applied to the life of the believer today by faith. There is a double imputation – my sins are placed on Christ and Christ’s righteousness is reckoned to me. Negatively, not only are my sins not counted against me, but, positively, Christ’s perfect righteous is given to us (2 Cor. 5:21).

It was this truth that was at the heart of the Roman Catholic response at The Council of Trent (1545-1563). In January 1547, under Pope III, the Decree Concerning Justification was written. Here are some of the key Canons Concerning Justification:

Canon 9. If anyone says that the sinner is justified by faith alone, meaning that nothing else is required to cooperate in order to obtain the grace of justification, and that it is not in any way necessary that he be prepared and disposed by the action of his own will, let him be anathema.

Canon 10. If anyone says that men are justified without the justice of Christ, whereby Her merited for us, or by that justice are formally just, let him be anathema.

Canon 11. If anyone says that men are justified either by the sole imputation of the justice of Christ or by the sole remission of sins, to the exclusion of the grace and the charity which is poured forth in their hearts by the Holy Ghost, and remains in them, or also that the grace by which we are justified is only the good will of God, let him be anathema.

Canon 12. If anyone says that justifying faith is nothing else than confidence in divine mercy, which remits sins for Christ's sake, or that it is this confidence alone that justifies us, let him be anathema.

Canon 13. If anyone says that in order to obtain the remission of sins it is necessary for every man to believe with certainty and without any hesitation arising from his own weakness and indisposition that his sins are forgiven him, let him be anathema.

Canon 14. If anyone says that man is absolved from his sins and justified because he firmly believes that he is absolved and justified, or that no one is truly justified except him who believes himself justified, and that by this faith alone absolution and justification are effected, let him be anathema.

Canon 15. If anyone says that a man who is born again and justified is bound ex fide to believe that he is certainly in the number of the predestined, let him be anathema.

Canon 16. If anyone says that he will for certain, with an absolute and infallible certainty, have that great gift of perseverance even to the end, unless he shall have learned this by a special revelation, let him be anathema.

Canon 24. If anyone says that the justice received is not preserved and also not increased before God through good works, but that those works are merely the fruits and signs of justification obtained, but not the cause of its increase, let him be anathema.

Canon 30. If anyone says that after the reception of the grace of justification the guilt is so remitted and the debt of eternal punishment so blotted out to every repentant sinner, that no debt of temporal punishment remains to be discharged either in this world or in purgatory before the gates of heaven can be opened, let him be anathema.

Canon 33. If anyone says that the Catholic doctrine of justification as set forth by the holy council in the present decree, derogates in some respect from the glory of God or the merits of our Lord Jesus Christ, and does not rather illustrate the truth of our faith and no less the glory of God and of Christ Jesus, let him be anathema.

One of the key promoters and defenders of the Council of Trent doctrine was Cardinal Robert Belarmine (1542-1621). He served as a doctrinal advisor to the Pope. On the issue of justification by grace alone through faith alone that is expressed in the assurance one has before the Lord due to Christ’s righteousness imputed to the sinner, Belarmine wrote the following (De justificatione 3.2.3):

The principle heresy of Protestants is that saints may obtain to a certain assurance of their gracious and pardoned state before God.

If you had been asked what the greatest heresy of Protestants was, how would you have answered? Would you have said it was the doctrine of assurance?

To the contrary, for Luther, the Reformers, the Reformation and Evangelicals, the cardinal truth of the gospel is justification by grace alone, through faith alone, in Christ alone. Any deviation from that compromises the gospel such that it is “another gospel” (Gal. 1:6-9).

This remains the greatest divide between Protestants (Evangelicals) and the Roman Catholic Church. I appreciate Sinclair Ferguson’s statement about this: “The Greatest of All Protestant Heresies”?

If justification is not by faith alone, in Christ alone, by grace alone — if faith needs to be completed by works; if Christ’s work is somehow repeated; if grace is not free and sovereign, then something always needs to be done, to be “added” for final justification to be ours. That is exactly the problem. If final justification is dependent on something we have to complete it is not possible to enjoy assurance of salvation. For then, theologically, final justification is contingent and uncertain, and it is impossible for anyone (apart from special revelation, Rome conceded) to be sure of salvation. But if Christ has done everything, if justification is by grace, without contributory works; it is received by faith’s empty hands — then assurance, even “full assurance” is possible for every believer.

By faith, I rest in the completed work of Christ and proclaim with bold confidence,

Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God. . . . There is therefore now no condemnation for those who are in Christ Jesus. (Rom. 5:1-2; 8:1).