A couple of books — Biblical books — shown by religious leader (5)
I believe the answer is:
abbot
'religious leader' is the definition.
(I've seen this before)
'a couple of books biblical books' is the wordplay.
'couple of' indicates the doubling of some letters.
'books' becomes 'b' (this could be a standard abbreviation which I don't know about).
'biblical books' becomes 'ot' (Old Testament).
'b' duplicated is 'bb'.
'a'+'bb'+'ot'='ABBOT'
'shown by' is the link.
(Other definitions for abbot that I've seen before include "Superior monk" , "Chief monk" , "Head of a community of monks" , "chap who'll be over order?" , "meeting Newton in Devon" .)