Struggle with belief (4)
I believe the answer is:
view
'belief' is the definition.
(view is a kind of belief)
'struggle with' is the wordplay.
'struggle' becomes 'vie' (to vie is to struggle or contend with).
'with' becomes 'w' (abbreviation).
'vie'+'w'='VIEW'
(Other definitions for view that I've seen before include "appearance" , "thinking" , "Prospect - opinion" , "See" , "Survey - opinion" .)