Devote attention to four consumed by religious sect (9)
I believe the answer is:
cultivate
'devote attention to' is the definition.
'four consumed by religious sect' is the wordplay.
'four' becomes 'iv' (roman numeral).
'consumed' becomes 'ate' (eating is a kind of consuming).
'by' is a charade indicator (letters next to each other).
'religious sect' becomes 'cult' (I've seen this before).
'iv'+'ate'='ivate'
'ivate' put after 'cult' is 'CULTIVATE'.
(Other definitions for cultivate that I've seen before include "Grow (crops)" , "Foster" , "Try to get in with" , "Promote" .)