The relationship between grace and works was a particular flash point in the theological debates of the Reformation, and while Protestants have broadly adopted the reformers’ understanding of grace, the legacy of their thought on good works has been more ambiguous. In his commentary on Romans 6:3, however, Lutheran theologian and pastor Johannes Brenz sets forth an argument characteristic of many reformers. He argues that while good works are not meritorious and do not contribute to the earning of salvation, they are nevertheless a necessary discipline and duty within the life of the believer and are demonstrable fruits in the lives of those who have been saved.

Good Works Are Our Duty, Not Our Merit

We can also learn from this passage what the role is of those who are baptized, namely, that since they have been absolved from sin and consecrated unto righteousness and life, they must no longer walk in sinful works.And yet, to do good works is the duty of a Christian, to which role a Christian is assigned. For this would be to profane one’s consecration and return to death. For this reason, even though good works are not merits that earn righteousness, they are nevertheless the fruits of righteousness and are to be done ex officio. For just like a king who is consecrated unto a kingdom does not “earn” the kingdom by issuing judgments in civil controversies, but rather obtains the kingdom either by succession, or by adoption, or by election, and yet to pronounce justice is the duty of a king, so also a Christian who is consecrated unto the heavenly kingdom does not earn that kingdom by good works, but has obtained it freely solely because of Christ through faith. And yet, to do good works is the duty of a Christian, to which role a Christian is assigned. It has not been ordained that we should merely eat and drink, but that we should do good works. Therefore they are not merits, but they are our duty.

Commentary on Romans 6:3 (1564).

Romans 1-8, ed. Gwenfair Walters Adams. Reformation Commentary on Scripture, NT vol. VII, p. 320.