When Bach found himself at Leipzig in 1723 as the new cantor at Thomaskirche, he had written only about 25 sacred cantatas in his time at Weimar and Cöthen. The punishing schedule of a weekly cantata plus works for the major feast days was particularly difficult during his first year in Leipzig. Many of his earlier works found their way into the repertoire that first season. Particularly difficult was the period right after Easter when there were, in a period of five days, three cantatas and a passion setting. Pentecost, too, was very intense, with Acension day, Pentecost, Whitmonday and Whit Tuesday all occurring in rapid succession. For the Easter and Pentecost season works, Bach reverted to secular works written in Cöthen rather than sacred works from Weimar. Bach’s Cöthen period is an interesting time in his development. There is no doubt that he had at his disposal very high-quality players during that period. The unaccompanied violin and cello music is from that period. All of the secular cantatas from Cöthen also demand virtuoso instrumentalists of great refinement. The Bach works that are arranged from secular to sacred are an interesting subset in his output. Not only does he set out on his task with great seriousness, but when examining this music one becomes aware of the great subtlety with which Bach considers his texts.
Most of our cantata today comes from a birthday serenade honoring Prince Leopold of Anhalt-Zerbst. The text is an elaborate and flattering portrayal of the wise prince as the great leader. While Bach doesn’t exactly simply convert the portrayal of the prince to the portrayal of Jesus, the text is based not only upon the famous passage in John: "God so loved the world," but the very interesting and controversial passage in Acts that tells of Jesus bypassing Judaism as a step to baptism. Although the cantata was originally for Whitmonday, the reading has been transferred to the Sundays after Pentecost in the new prayerbook.
Our cantata begins with the tenor solemnly intoning the idea that we are created in the exalted image of God. The aria that follows for two flutes and strings is typical of the detailed elegance and grace of the best of the Cöthen pieces. Certainly the elaborate filigree of the top strings and flutes not only illustrates the "Hallowed spirit" but also the tuning of the strings and lyres.
The alto aria that follows is an unusual change of character, spiky, almost harsh in tone. The high point of this beautiful cantata is the modulating duet. (It begins in D and ends in A). No other Bach cantata movement ends in a different key than it begins in. The three verses – a "This is true, and this is true, therefore this must be true" – not only perfectly reflect the paean to Leopold but perfectly fit the structure of the sacred text. The sweetness of the strings in the first verse is replaced by ethereal flutes with no bass and the strings assuming a bass line function in the second verse. The third verse brings together all of the elements together with a delightful skittering string obbligato. The following duet-recitative is the only newly composed section of our cantata. The final chorus is an expansion of a duet in the secular cantata. We have added a beautiful setting of the chorale "Herzlich lieb" that comes from another cantata (BWV 174) for this same day.