In this chorale prelude Telemann writes broken chords for the right hand, while the chorale melody is played with the left hand. The festive text of the first verse of this chorale led me initially to play it in a rather high tempo. After that I played it in a much slower tempo. Both versions have their own merit. The faster performance emphasizes the more festive character of the text, the slower performnce more the dignity and importance of the gospel. Well, these are just words. Let the music speak for itself and choose your own preference.
This is the slower performance.
The recording was done with the Hauptwerk software and the sampleset, made by Voxus, of the Müller organ in the Sint Bavokerk, Haarlem (http://www.voxusorgans.com/en/product/haarlem).
Score available here: http://partitura.org/index.php/georg-philipp-telemann-nun-freut-euch-lieben-christen-gemein-twv-3151