Sci-fi writer's bit of exaltation in religious group (6)
I believe the answer is:
clarke
'exaltation in religious group' is the definition.
The definition suggests a singular noun which matches the answer.
'sci-fi writer's bit' is the wordplay.
I cannot quite see how this works, but
'bit' could be 'lark' (I have seen 'bit of fun' mean 'lark' so perhaps 'bit' could also mean 'lark') and 'lark' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for clarke that I've seen before include "Arthur C. --, author" , "composer of Trumpet Voluntary" , "Roddy Doyle's Paddy" , "Arthur C --, writer" .)