Ditch sermon? That's bad for body of believers (11)
I believe the answer is:
christendom
'body of believers' is the definition.
(the Christian world)
'ditch sermon? that's bad' is the wordplay.
'that's bad' indicates an anagram.
'ditch'+'sermon'='ditchsermon'
'ditchsermon' with letters rearranged gives 'CHRISTENDOM'.
'for' acts as a link.
(Other definitions for christendom that I've seen before include "all the faithful" , "Worldwide followers of Jesus" , "Area historically dominated by the Church" , "body of believers" .)