Johann Sebastian Bach, the well-tempered composer, worked throughout his career for what he called "a well-ordered church music to the glory of God." (1) It was not always easy to achieve this goal because he often had to contend with church and city councils (they were one and the same) that did not always deliver what they promised, or pietist pastors and a rationalist rector of the Thomasschule in Leipzig who believed that church music exists primarily to edify the congregation (Bach thought church music existed soli Deogloria--"to the glory of God alone"). But, as Bach was at the top of his craft as a musician, he also was an astute theologian in the orthodox Lutheran tradition. To obtain the job of cantor at the Thomasschule in Leipzig he had to pass not only a musical audition but also a theological examination (conducted in Latin) given by the theology faculty of the University of Leipzig on behalf of the ecclesiastical consistory. Indications are that he passed with flying colors. (2). Bach was, in the words of Christoph Wolff, "the learned musician." Bach's personal library contained hundreds of musical scores and works on music theory. He also had an extensive theological library that included two editions of Martin Luther's complete works and biblical commentaries by orthodox Lutheran theologians. His copy of the Calov Bible of 1681 was well underlined and annotated. This gives us some idea of the study Bach did in preparation for composing his church cantatas. Considering the expense of books in those days, and that the Leipzig cantor bought them out of his own salary, we see how "learned" he actually was. Wolff comments that "for Bach, theological and musical scholarship were two sides of the same coin: the search for divine revelation.or the quest for God." (3) It is clear from this data that Bach took seriously the theological dimensions of his church office.
