It's about religious groups having quiet values (8)
I believe the answer is:
respects
'values' is the definition.
('respect' can be a synonym of 'value')
'it's about religious groups having quiet' is the wordplay.
'it's about' becomes 're' (regarding).
'religious groups' becomes 'sects' (sect is a type of religious group).
'having' indicates putting letters inside.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'sects' placed around 'p' is 'spects'.
're'+'spects'='RESPECTS'
(Other definitions for respects that I've seen before include "Compliments" , "Admires" , "what may be paid by callers" , "Has high opinion of" , "details" .)