Cantata no. 50: Nun ist das Heil und die Kraft, BWV.50

Nun ist das Heil und die Kraft, BWV 50, is a choral movement long attributed to Johann Sebastian Bach and assumed to be part of a lost cantata.

The text and scoring point towards its being written for a Michaelmas celebration. In Leipzig, where Bach was employed from 1723, the feast was celebrated with large-scale church music and also a trade fair. American Bach scholar William H. Scheide suggested that the work was written in 1723, Bach's first year in the city. However, the exact dates of composition and first performance are unknown.