Voluntary works—besides, over and above God’s commandments—which they call works of supererogation, cannot be taught without arrogancy and impiety. For by them men do declare that they do not only render unto God as much as they are bound to do, but that they do more for his sake than of bounden duty is required; whereas Christ saith plainly: When you have done all that is commanded you, say, We are unprofitable servants.
This is the same in the Episcopal Articles. Supererogation means “beyond the call of duty.” It is part of the Roman Catholic doctrine of indulgences in which the acts of supererogation by the saints have built up a treasury of merit upon which the Church can draw to exempt sinners from acts of penance for their sins. Also included are the counsels of perfection: poverty, chastity, and obedience which are thought to earn merit in the eyes of God because they go beyond Christian duty. The arrogance mentioned in the Article is due to the idea that God owes us a debt if we perform such works.
Making a Difference in the World 