Decency in good people (5)
I believe the answer is:
grace
'decency' is the definition.
(thesaurus)
'good people' is the wordplay.
'good' becomes 'g' (abbreviation).
'people' becomes 'race' (**).
'g'+'race'='GRACE'
'in' acts as a link.
(Other definitions for grace that I've seen before include "Prayer of thanks before/after a meal" , "Honour" , "Meal blessing" , "Elegance; blessing" , "kindness" .)