Burns and marks on outside of church (8)
I believe the answer is:
scorches
'burns' is the definition.
(scorch is a kind of burn)
'marks on outside of church' is the wordplay.
'marks' becomes 'scores' ('score' can be a synonym of 'mark'**).
'on outside of' is an insertion indicator.
'church' becomes 'ch' (common abbreviation).
'scores' enclosing 'ch' is 'SCORCHES'.
'and' is the link.
(Other definitions for scorches that I've seen before include "Burns slightly" , "Burns on the surface" .)