Strange end in religious service? Nonsense (7)
I believe the answer is:
madness
'nonsense' is the definition.
(thesaurus)
'strange end in religious service?' is the wordplay.
'strange' is an anagram indicator.
'in' means one lot of letters goes inside another.
'religious service?' becomes 'mass' (I've seen this before).
'end' anagrammed gives 'dne'.
'dne' inserted within 'mass' is 'MADNESS'.
(Other definitions for madness that I've seen before include "fury" , "Lunacy - ska/pop band" , "Folly" , "Dementia" , "Absurdity" .)