Belief can be source of hope in troubled times (6)
I believe the answer is:
theism
'belief' is the definition.
(theism is a kind of belief)
'source of hope in troubled times' is the wordplay.
'source of' says to take the initial letters.
'in' is an insertion indicator.
'troubled' indicates anagramming the letters.
The initial letter of 'hope' is 'h'.
'times' with letters rearranged gives 'teism'.
'h' going within 'teism' is 'THEISM'.
'can be' is the link.
(Other definitions for theism that I've seen before include "Belief in a creator" , "Belief in a deity" , "of faith" , "The doctrine or belief in the existence of a God or gods" , "Belief in existence of a God revealed to man" .)