Dedicated action inspiring five religious books (7)
I believe the answer is:
devoted
'dedicated' is the definition.
(synonyms)
'action inspiring five religious books' is the wordplay.
'action' becomes 'deed' (deed is a kind of action).
'inspiring' indicates putting letters inside.
'five' becomes 'V' (Roman numeral).
'religious books' becomes 'OT' (Old Testament).
'v'+'ot'='vot'
'deed' placed around 'vot' is 'DEVOTED'.
(Other definitions for devoted that I've seen before include "Dedicated or wholly given up to" , "Strongly attached (to)" , "Loving and loyal" , "Faithful" .)