Purge lists screened by religious establishment (7)
I believe the answer is:
cleanse
'purge' is the definition.
(I've seen this before)
'lists screened by religious establishment' is the wordplay.
'lists' becomes 'leans' (I've seen this in other clues).
'screened by' is an insertion indicator.
'religious establishment' becomes 'ce' (I can't justify this - if you can you should give a lot more credence to this answer).
'leans' placed within 'ce' is 'CLEANSE'.
Can you help me to learn more?
(Other definitions for cleanse that I've seen before include "Disinfect" , "clear of muck" , "Make thoroughly clean" , "subject to purification" , "carry out purification" .)