Flask church needed to hold a service (6)
I believe the answer is:
carafe
'flask' is the definition.
(I've seen this before)
'church needed to hold a service' is the wordplay.
'church' becomes 'CE' (abbreviation for Church of England).
'needed to hold' is an insertion indicator (to hold can mean to receive or contain).
'service' becomes 'RAF' (Royal Air Force).
'a'+'raf'='araf'
'ce' enclosing 'araf' is 'CARAFE'.
(Other definitions for carafe that I've seen before include "Water-jar" , "Wide-necked bottle for water or wine" , "in which one has wine?" , "Bottle with a stopper, for wine or water" , "keeper of wine" .)