I doubt that on that wonderful Judgment Day any who are Christ’s will be thinking about, looking upon, or even dare to offer up their best works of sanctification. Then we will be robed both within and without in only the Righteousness of the Lamb; and yet even our blood-washed garments of righteousness will not draw our attention. Rather, all eyes will be fixed on him who died for us.
Concerning works of believers and their justification, John Calvin writes in The Necessity of Reforming the Church:
Lastly, there was another most pestilential error, which not only occupied the minds of men, but was regarded as one of the principal articles of faith, of which it was impious to doubt, viz., that believers ought to be perpetually in suspense and uncertainty as to their interest in the divine favor. By this suggestion of the devil, the power of faith was completely extinguished, the benefits of Christ’s purchase destroyed, and the salvation of men overthrown. For, as Paul declares, that faith only is Christian faith which inspires our hearts with confidence, and emboldens us to appear in the presence of God, (Romans 5:2.) On no other view could his doctrine in another passage be maintained, viz., that
“we have received the Spirit of adoption, whereby we cry, Abba, Father,” (Romans 8:15.)
But what is the effect of that hesitancy which our enemies require in their disciples, save to annihilate all confidence in the promises of God? Paul argues, that
“If they which are of the law be heirs, faith is made void, and the promise made of none effect,” (Romans 4:14.)
Why so? Just because the law keeps a man in doubt, and does not permit him to entertain a sure and firm confidence. But they, on the other hand, dream of a faith, which, excluding and repelling man from that confidence which Paul requires, throws him back upon conjecture, to be tossed like a reed shaken by the wind. And it is not surprising that after they had once founded their hope of salvation on the merit of works, they plunged into all this absurdity. It could not but happen, that from such a precipice they should have such a fall. For what can man find in his works but materials for doubt, and, finally, for despair? We thus see how error led to error…
It would seem that the error Calvin refers to was similar to the one Paul confronted in his letter to the Galatians. Those first century believers had reverted to a grace plus works understanding of salvation, i.e. faith in Christ’s death and resurrection for forgiveness of sins and justification – to which was added grace-enabled works under the Law for final salvation.