Ich weiß, daß mein Erlöser lebt (I know that my Redeemer lives), TWV 1:877, BWV 160, is a church cantata composed around 1725 by Georg Philipp Telemann for Easter Sunday, formerly attributed to Johann Sebastian Bach.
A manuscript copy from the 18th century by Bach's student Heinrich Nikolaus Gerber identified Bach as the composer of the work, and on this basis it was given a BWV number in an 1886 catalogue. However, by the 1950s two manuscripts from the 18th century had been found that attributed the work to Telemann; the piece was given the new number TWV 1:877. It is one of the works that Bach had copied out so that he could perform it as part of his employment in Leipzig.
The piece is a solo cantata with lyrics by Erdmann Neumeister. It is scored for solo tenor voice, violin, bassoon, and basso continuo. It has five movements (all in the key of C major), alternating between arias and recitatives.