“The law is to the flesh like a whip to an idle and balky ass, to arouse it to work.”41 The Solid Declaration reiterates that Christians also need the Law in order that they might not, under the deception of being led by the Spirit, establish rules of piety without the authority of Scripture. Furthermore, the teaching of the Law is needed to keep the Christian humble toward his or her own works, and the Law acts as “a mirror” revealing the impurities even of the believer’s works. Yet the believer