Two churches in liaison? (7)
I believe the answer is:
romance
'liaison?' is the definition.
(thesaurus)
'two churches' is the wordplay.
'two churches' means two substitutions for 'church'.
'church' becomes 'Roman Church' (Roman Church is an example).
'church' becomes 'CE' (abbreviation for Church of England).
'roman'+'ce'='ROMANCE'
'in' is the link.
(Other definitions for romance that I've seen before include "Amorous relationship" , "Lie" , "fairy story?" , "marriage?" , "Love-story" .)