proper understanding of good works

For especially in these last times it is no less needful to admonish men to Christian discipline [to the way of living aright and godly] and good works, and remind them how necessary it is that they exercise themselves in good works as a declaration of their faith and gratitude to God, than that the works be not mingled in the article of justification; because men may be damned by an Epicurean delusion concerning faith, as well as by papistic and Pharisaic confidence in their own works and merits. -- Epitome, Formula of Concord