Religious education story very easy, initially, to replace (7)
I believe the answer is:
relieve
'replace' is the definition.
(thesaurus)
'religious education story very easy initially' is the wordplay.
'religious education' becomes 'RE' (abbreviation).
'story' becomes 'lie' (story can mean a fabrication).
'initially' suggests taking the first letters.
The first letters of 'very easy' is 've'.
're'+'lie'+'ve'='RELIEVE'
'to' is the link.
(Other definitions for relieve that I've seen before include "Palliate" , "Take over work from someone" , "Take a job over from - bring aid" , "Make less tedious, bring aid to (besieged place)" , "Alleviate pain or stress" .)