A terribly nice part of the bible - very old (7)
I believe the answer is:
ancient
'very old' is the definition.
(I've seen this before)
'a terribly nice part of the bible' is the wordplay.
'terribly' indicates anagramming the letters.
'part of the bible' becomes 'nt' (New Testament).
'nice' with letters rearranged gives 'ncie'.
'a'+'ncie'+'nt'='ANCIENT'
(Other definitions for ancient that I've seen before include "from olden times" , "Dating from long ago" , "Historic standard" , "Early" , "very old boy?" .)