Thematic Bible: Supererogation

Therefore, thou son of man, say to the children of thy people, The righteousness of the righteous shall not deliver him in the day of his transgression: as for the wickedness of the wicked, he shall not fall by it in the day that he turneth from his wickedness; neither shall the righteous be able to live for his righteousness in the day that he sinneth. When I shall say to the righteous, that he shall surely live; if he shall trust to his own righteousness, and commit iniquity, all his righteousnesses shall not be remembered; but for his iniquity that he hath committed, he shall die for it.

So likewise ye, when ye shall have done all the things which are commanded you, say, We are unprofitable servants: we have done that which it was our duty to do. Verse ConceptsCommands, in NTServants, GoodDuty