Thematic Bible: Supererogation

"And you, son of man, say to your people, The righteousness of the righteous shall not deliver him when he transgresses, and as for the wickedness of the wicked, he shall not fall by it when he turns from his wickedness, and the righteous shall not be able to live by his righteousness when he sins. Though I say to the righteous that he shall surely live, yet if he trusts in his righteousness and does injustice, none of his righteous deeds shall be remembered, but in his injustice that he has done he shall die.

So you also, when you have done all that you were commanded, say, 'We are unworthy servants; we have only done what was our duty.'" Verse ConceptsCommands, in NTServants, GoodDuty