Tiny changes to adopt church's point (6)
I believe the answer is:
nicety
'point' is the definition.
(I have seen 'Subtle point' mean 'nicety' so perhaps 'point' could also mean 'nicety')
'tiny changes to adopt church's' is the wordplay.
'changes' indicates anagramming the letters.
'to adopt' indicates putting letters inside.
'church' becomes 'ce' (abbreviation for Church of England).
'tiny' is an anagram of 'nity'.
'nity' placed around 'ce' is 'NICETY'.
(Other definitions for nicety that I've seen before include "Fine point or subtlety" , "Subtle difference" , "Minute distinction; subtlety" , "Exactitude" , "Judged to a . . . . . . - with precision" .)