Culminating point: that's getting married in a church (4)
I believe the answer is:
acme
'culminating point' is the definition.
(I've seen this before)
'married in a church' is the wordplay.
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'in' is an insertion indicator.
'church' becomes 'CE' (Church of England).
'a'+'ce'='ace'
'm' inserted inside 'ace' is 'ACME'.
'that's getting' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for acme that I've seen before include "Peak of excellence" , "Highest stage of development" , "Culmination" , "Summit, crowning point" , "Height of achievement" .)