Religious split? (6,2,5)

I believe the answer is:

breach of faith

I'm a little stuck... Click here to teach me more about this clue!

'religious' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'split?' is the wordplay.
I cannot quite understand how this works, but
'split?' could be 'breach' (I've seen this before) and 'breach' is present in the answer.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in The Irish News.

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