Acknowledge period embracing Religious Education (5)
I believe the answer is:
agree
'acknowledge' is the definition.
(thesaurus)
'period embracing religious education' is the wordplay.
'period' becomes 'age' (age is a kind of period).
'embracing' is an insertion indicator.
'religious education' becomes 'RE' (abbreviation).
'age' enclosing 're' is 'AGREE'.
(Other definitions for agree that I've seen before include "Settle" , "Square" , "Give consent" , "Allow" , "Accord, match" .)