Indicate peculiar need to grasp part of the Bible (6)
I believe the answer is:
denote
'indicate' is the definition.
(I've seen this in another clue)
'peculiar need to grasp part of the bible' is the wordplay.
'peculiar' indicates anagramming the letters (a peculiar or strange ordering of the letters).
'to grasp' is an insertion indicator.
'part of the bible' becomes 'OT' (Old Testament).
'need' anagrammed gives 'dene'.
'dene' enclosing 'ot' is 'DENOTE'.
(Other definitions for denote that I've seen before include "Indicate, signify" , "Designate" , "Indicate, be a sign of" , "Need to (anag) - indicate" , "show" .)