Ich lebe, mein Herze, zu deinem Ergötzen (I live, my heart, for your pleasure),[1] BWV 145, is a five-movement church cantata on a libretto by Picander which Johann Sebastian Bach, as its composer, probably first performed in Leipzig on Easter Tuesday, 19 April 1729.

As a seven-movement pasticcio, with one of the added movements composed by Georg Philipp Telemann, it is an Easter cantata known as So du mit deinem Munde bekennest Jesum (as it was published in the 19th century)[2] or as Auf, mein Herz!

[5][6] The closing chorale is the fourteenth and final stanza of Nikolaus Herman's Easter hymn "Erschienen ist der herrlich Tag".

[7] The five movements on Picander's text seem rather short for the purpose, therefore Alfred Dürr suggests that Bach might have added a sinfonia, as in two cantatas of the period, BWV 174 and 188, admitting that there is no source to substantiate it.

[10] The cantata is scored for three vocal soloists (soprano, tenor and bass), a four-part choir, trumpet, flauto traverso, two oboe d'amore, two violins, viola and basso continuo.

[6][11] The cantata is closed by a four-part setting of the last stanza of the Easter hymn "Erschienen ist der herrlich Tag".