Division in church is accepted by NCO (6)
I believe the answer is:
schism
'division' is the definition.
(schism is a kind of division)
'church is accepted by nco' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'accepted by' indicates putting letters inside.
'nco' becomes 'sm' (abbreviation for sergeant major, a type of NCO).
'ch'+'is'='chis'
'chis' inserted into 'sm' is 'SCHISM'.
'in' acts as a link.
(Other definitions for schism that I've seen before include "Split (usually in church)" , "(Ecclesiastical) division" , "Split, rift" , "Split or heresy" , "Difference in religious beliefs within a church" .)