High priest found in some religions (3)
I believe the answer is:
eli
'high priest' is the definition.
(biblical figure)
'in some religions' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ELI' is hidden in the letters of 'some religions'.
'found' is the link.
(Other definitions for eli that I've seen before include "Biblical teacher of Samuel" , "Old Testament high priest" , "Priest at Shiloh (Samuel)" , "Teacher of prophet Samuel" , "Shiloh priest (Bible)" .)