This work investigates the core question of whether the Roman Catholic sacramental system, as practiced in the 16th century, aligns with the biblical definition of a sacrament. Martin Luther, a German monk and theologian, utilizes his expertise in scripture and canon law to challenge the prevailing ecclesiastical structure of his time. He argues that the church has effectively held the gospel captive by expanding the number of sacraments beyond those explicitly instituted by Christ. The text serves as a foundational critique of medieval sacramental theology and a call for a return to a simplified, scripture-based practice.

Historians and theologians identify this text as one of the most significant documents of the Protestant Reformation, marking a definitive break from medieval scholasticism. Readers frequently note the dense, polemical nature of the prose, which reflects the intense theological debates of the early 16th century.