Darzu ist erschienen der Sohn Gottes (For this the Son of God appeared), BWV 40, is a church cantata by Johann Sebastian Bach. He composed it in 1723, his first year in Leipzig, for the Second Day of Christmas, and first performed it on 26 December that year in both main churches, Thomaskirche and Nikolaikirche. It was the first Christmas cantata Bach composed for Leipzig. The title of the cantata also appears in more modern German as Dazu ist erschienen der Sohn Gottes. Bach used the opening chorus for the concluding Cum Sancto Spiritu in his 1738 Missa in F major, BWV 233.