Where it's said Hindu might seek guidance for trespasser (7)
I believe the answer is:
invader
'trespasser' is the definition.
(I know that encroacher is a type of interloper)
I don't understand the remainder of the clue.
(Other definitions for invader that I've seen before include "far from welcome guest" , "One attacks" , "One entering by force" , "One entering as an enemy" , "Attacker from outside" .)