This Theological Commentary is the first full-length work in English to consider Johann Sebastian Bach ?s St John Passion in its entirety, both the words and the music. Bach ?s oratorio is a globally popular musical work, and a significant expression of Lutheran theology. The commentary explains the Biblical and poetic text, and its musical setting, line by line. Bach ?s Passion is shown to be the work of a master craftsman and trained theologian, in the collaborative and cultural milieu of eighteenth-century, Lutheran Leipzig. For the first time, this work makes much German scholarship available in English, including archival sources, and includes a new scholarly translation of the libretto. The musical and theological terms are explained, to enable an interdisciplinary understanding of the Passion ?s meaning and continued significance.