Hope for religious group keeping quiet (8)
I believe the answer is:
prospect
'hope' is the definition.
(thesaurus)
'for religious group keeping quiet' is the wordplay.
'for' becomes 'pro' (as in being 'pro' or in favour of something).
'religious group' becomes 'sect' (eg a religious sect).
'keeping' indicates putting letters inside (some letters kept inside).
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'sect' going around 'p' is 'spect'.
'pro'+'spect'='PROSPECT'
(Other definitions for prospect that I've seen before include "Search for gold - view - scene - probability" , "Chance of success" , "Extensive landscape" , "likelihood of event taking place" , "Likelihood of a future event occurring" .)