Apostle lost lot in section of the church (4)
I believe the answer is:
apse
'section of the church' is the definition.
'apse' can be an answer for 'church' (I've seen this before). I'm not certain of the 'section of the' bit.
'apostle lost lot' is the wordplay.
'lost' suggests deleting specific letters.
'apostle' with 'lot' taken away is 'APSE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for apse that I've seen before include "Rounded end of building" , "Recess with domed rof in a church" , "Church recess in lapsed condition" , "part of cathedral" , "Recess in church wall" .)