Class answer good man in church (5)
I believe the answer is:
caste
'class' is the definition.
(caste is a kind of class)
'answer good man in church' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'good man' becomes 'st'.
'in' indicates putting letters inside.
'church' becomes 'CE' (abbreviation for Church of England).
'a'+'st'='ast'
'ast' inserted within 'ce' is 'CASTE'.
(Other definitions for caste that I've seen before include "Social class or rank" , "Persons with class" , "Hereditary social class among Hindus" , "Hereditary class (in India)" , "Large, long-necked, wading bird" .)