Johann Sebastian Bach is often identified as the epitome of the Baroque era and contributed significantly to the practice and theoretical development of Western music. He composed numerous musical works, including more than 500 vocal compositions such as sacred and secular cantatas, motets, masses and passions. The majority of Bach's cantatas date back to his post in Leipzig. Although he is considered to have written five cantata cycles, only the first three are practically completed; the other two are either lost or cannot be attributed to Bach. Bach's second year in Leipzig is considered his most prolific. On the 14th Sunday after Trinity in 1724, Bach created Bwv. 78, Jesu, der du meine Seele. Using the chorale melody and the hymn text written by Johann Rist in 1641, Bach incorporated the entire first and twelfth verses into the first and seventh movements of the cantata. Additionally, Bach paraphrased parts of Rist's poetry in movements three and five; the author of the remaining text remains unknown. This paragraph is an excellent example of Bach's ability to interpret and musically enhance religious texts. The liturgical readings for this particular Sunday included the parable of Jesus and the cleansing of the lepers. By retaining the key of G minor, the overall mood of the chorale can be perceived as uncertain and uncertain, which is also supported by the text "Herr, ich glaube, hilf mir Schwachen" (Lord, I believe, help me in my weakness). As demonstrated in the previous movement, one can fight for the conviction of Christ; however, without His love, we are destined to wander aimlessly in this world. This is the weakness mentioned in the text. However, as the chorale progresses towards the last two cadential points of bars 14-16, the cantata ends in the parallel key of G major. The use of the Picardy third illuminates the final text, "in der süssen Ewigkeit" (in sweet eternity), and brings a sense of resolution and hope to the piece..