Steal from post office by a church (5)
I believe the answer is:
poach
'steal' is the definition.
(I've seen this in another clue)
'post office by a church' is the wordplay.
'post office' becomes 'po' (abbreviation).
'by' means one lot of letters go next to another.
'church' becomes 'ch' (abbreviation on maps etc).
'po'+'a'+'ch'='POACH'
'from' acts as a link.
(Other definitions for poach that I've seen before include "Track down" , "Cook in hot water" , "Appropriate" , "Acquire illegally" , "Take game illegally from land or water" .)