Burning pictures outside sanctuary (6)
I believe the answer is:
ardent
'burning' is the definition.
(both can mean passionate)
'pictures outside sanctuary' is the wordplay.
'pictures' becomes 'art'.
'outside' is an insertion indicator.
'sanctuary' becomes 'den' (I've seen this in other clues).
'art' enclosing 'den' is 'ARDENT'.
(Other definitions for ardent that I've seen before include "Fervid" , "Intensely enthusiastic" , "Fiery and zealous" , "Zealous - ranted (anag)" , "Passionate and glowing" .)