One million continue accepting one saint’s beliefs (11)
I believe the answer is:
impressions
'beliefs' is the definition.
(I know this)
'one million continue accepting one saint's' is the wordplay.
'one million' becomes 'im' (resembles 1m, 1 million).
'continue' becomes 'press on' (to press on with something is to continue with it).
'accepting' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'saint' becomes 's'.
'presson' going around 'i' is 'pression'.
'im'+'pression'+'s'='IMPRESSIONS'
(Other definitions for impressions that I've seen before include "opinions" , "Impersonations" , "Popular books may go through several of these" .)