Go in search of follower of religion, we hear (4)
I believe the answer is:
seek
'go in search of' is the definition.
'follower of religion we hear' is the wordplay.
'follower of religion' becomes 'sikh' (follower of Sikhism).
'we hear' indicates a 'sounds like' (homophone) clue.
'sikh' is a homophone of 'SEEK'.
(Other definitions for seek that I've seen before include "Go looking for" , "Attempt - search" , "Try to locate or reach" , "Try to find" , "Hunt, look for" .)