Theft of tin at church (6)
I believe the answer is:
snatch
'theft' is the definition.
(snatch can mean to steal)
'tin at church' is the wordplay.
'tin' becomes 'Sn' (Sn is the chemical symbol for tin).
'church' becomes 'ch' (common abbreviation).
'sn'+'at'+'ch'='SNATCH'
'of' is the link.
(Other definitions for snatch that I've seen before include "Seize; musical fragment" , "Filch" , "Quickly grasp - fragment of song" , "Seize - fragment of verse" , "Grasp hurriedly" .)