Follow the master's belief (5)
I believe the answer is:
dogma
'belief' is the definition.
(dogma is a kind of belief)
'follow the master's' is the wordplay.
'follow' becomes 'dog' (I've seen this before).
'the master' becomes 'ma'.
'dog'+'ma'='DOGMA'
(Other definitions for dogma that I've seen before include "Code of belief" , "Fixed belief" , "Laid down set of (religious) principles" , "Authoritative doctrine" , "A religious belief" .)