Thematic Bible: Supererogation

Thou son of man, tell the children of thy people, 'The righteousness of the righteous shall not save him, whensoever he turneth away unfaithfully. Again, the wickedness of the wicked shall not hurt him, whensoever he converteth from his ungodliness. And the righteousness of the righteous, shall not save his life, whensoever he sinneth. If I say unto the righteous, that he shall surely live, and so he trust to his own righteousness, and do sin: then shall his righteousnesses be no more thought upon, but in the wickedness that he hath done he shall die.

So likewise ye, when ye have done all those things which are commanded unto you, say, 'We are unprofitable servants. We have done that which was our duty to do.'" Verse ConceptsCommands, in NTServants, GoodDuty