Forcefully eject fifth parishioner seated there in church (4)
I believe the answer is:
spew
'forcefully eject' is the definition.
'spew' can be an answer for 'eject' (I've seen this in another clue). I am unsure of the 'forcefully' bit.
'fifth parishioner seated there in church' is the wordplay.
'fifth parishioner' becomes 's' (5th letter of 'parishioner').
'seated there in church' becomes 'pew' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
's'+'pew'='SPEW'
Can you help me to learn more?
(Other definitions for spew that I've seen before include "Gush forth, vomit" , "Be sick" , "Forcibly eject" , "Casst out in a stream" , "Erupt, eject" .)