Plot everything with setter surrounded by books about religion (9)
I believe the answer is:
allotment
'plot' is the definition.
(I've seen this before)
'everything with setter surrounded by books about religion' is the wordplay.
'everything' becomes 'all' (I've seen this before).
'with' is an insertion indicator.
'setter' becomes 'me' (the setter of the clue).
'surrounded by' becomes 'ot' (I am not sure about this - if you are sure you should believe this answer much more).
'books about religion' becomes 'nt' (New Testament).
'ot'+'nt'='otnt'
'me' put within 'otnt' is 'otment'.
'all'+'otment'='ALLOTMENT'
Can you help me to learn more?
(Other definitions for allotment that I've seen before include "Distribution of shares" , "grant?" , "Allowance" , "Share - small piece of land rented for cultivation" , "allocation" .)