One dispenses with finally being taken in by church obscurity (7)
I believe the answer is:
chemist
'one dispenses' is the definition.
(person who dispenses drugs)
'with finally being taken in by church obscurity' is the wordplay.
'finally' suggests the final letters.
'being taken in by' is an insertion indicator.
'church' becomes 'ce' (abbreviation for Church of England).
'obscurity' becomes 'mist'.
The last letter of 'with' is 'h'.
'h' put within 'ce' is 'che'.
'che'+'mist'='CHEMIST'
(Other definitions for chemist that I've seen before include "Drug store" , "Employee in pharmacy" , "Nobel, say" , "Seller of medications" , "Drugs/toiletries shop" .)