Employed in religious education (4)
I believe the answer is:
used
'employed' is the definition.
('use' can be a synonym of 'employ')
'in religious education' is the wordplay.
'in' indicates a hidden word.
'USED' is hidden within 'religious education'.
(Other definitions for used that I've seen before include "Of clothes or cars, second-hand" , "Pre-loved" , "like majority of cars?" , "Hand-me-down" , "Took advantage of" .)