… part of church cut off on Sunday, creating opportunities (7)
I believe the answer is:
chances
'opportunities' is the definition.
('chance' can be a synonym of 'opportunity')
'part of church cut off on sunday' is the wordplay.
'part of church' becomes 'chancel' (area of a church).
'cut off' means to remove the last letter.
'on' says to put letters next to each other.
'sunday' becomes 's'.
'chancel' with its final letter taken off is 'chance'.
'chance'+'s'='CHANCES'
'creating' is the link.
(Other definitions for chances that I've seen before include "Runs a risk" , "Opportunities or risks" .)