Rent's a turning point for some of the church (8)
I believe the answer is:
transept
'some of the church' is the definition.
I can't tell whether this defines the answer.
'rent's a turning point' is the wordplay.
'turning' indicates anagramming the letters.
'point' becomes 'pt' (abbreviation for point).
'rents'+'a'='rentsa'
'rentsa' with letters rearranged gives 'transe'.
'transe'+'pt'='TRANSEPT'
'for' is the link.
Can you help me to learn more?
(Other definitions for transept that I've seen before include "always running north to south" , "Side part of a church" , "Section of church" , "Cross-aisle in church" , "Part of a church at right angles to the nave" .)