Belief is a funny thing.

[ But John could just ask them; he has his own feelings on the matter. ]

Heather knows God exists but doesn't believe much in Her. [ Which is the fault of her insane mother more than anything. The Order was tainted when in the control of Dahlia, but there's no need to get into all of that. ] Maria has most likely witnessed the miracles that God created but did not connect them to Her.

I'm sure they know She lives as much as any deity can live, but they have no faith.