Religious rift (6)
I believe the answer is:
schism
'religious rift' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for schism that I've seen before include "Formal separation of a church into two churches" , "Split over doctrinal beliefs" , "Religious division, breach" , "(Ecclesiastical) division" , "Church disunity" .)