That’s pretty much his position as I recall it from Whys of a Philosophical Scrivener; he believed because he really, really wanted to and didn’t even pretend it was rational.
Epistemology?
Maybe if the OP knows which branch of religion his forgotten term is, that would help. Western religion? Eastern? Middle Eastern?
He’s talking about Christianity. He says:
I think the difficulty may be, though, that Ornery Bob misunderstands the term, and it doesn’t actually have quite the meaning he thinks it does. Therefore, when he explains what he thinks the meaning is, we can’t spot the term. He says:
It’s not a mainstream Christian position that “faith matters and reason doesn’t”; generally Christianity insists that it is rational, and is rightly judged against that yardstick. And, while Christianity affirms that God is beyond understanding, the corollary is not that it’s “dumb even to try” , but rather than our attempts must be attended with a degree of humility and a recognition of their inadequacy.
“Ineffable” (cannot be expressed or described in language) and “transcendent” (above and distinct from the universe) have already been suggested. They’re commonly employed in theological discussion to discuss Deity. Neither of them is the term the OP recollects, and neither of them implies any rejection of reason.
I’m convinced the word the OP is looking for exists, but I can’t put my finger on it. One sometimes hears ‘transrational’, especially in the context of Christian existentialism (think Kierkegaard). Another word I think is sometimes used in a similar way is ‘numinous’.
I’m pretty sure it was here on the SDMB that I learned the term cognitive dissonance. I was seriously not expecting this thread to get so long without it.
That’s certainly relevant, but it’s invariably a derogatory term. With reference to the OP, nobody would use it to justify their own belief system.
“Faith”
Is they mystery word describing the rational thought or the religious thought? I thought it was the former, but most of the replies seem to assume the later.
That is, is the nun telling you that your thought is X, or that her thought is X?
Yardstick?
That’s not what cognitive dissonance means. Cognitive dissonance is holding two contradictory beliefs true at the same time, or rather the negative feelings brought about by that. “This is beyond human reasoning, just accept it” is a silly but non-contradictory statement. I suppose you could file it under irony, since the notion that something could be beyond human reasoning is itself a product of human reasoning.
Nuns reading the Bible? That never happened in my Catholic school days.
Regardless, I never heard a priest or nun say that reason should not be used- merely that some things are still mysteries.
Theologians can and do use reason- but assuming God exists, there are things we can only know about Him if He chooses to reveal them.
Gödel’s incompleteness theorem?
Regards,
Shodan
No that would be impenetrable.
If a woman cannot have babies is she impregnable or inconceivable?
Yes that word does mean what I think it means.
“Faith”, while not a mysterious term only used in this circumstance, is certainly the word that was held up to me every time I started asking questions in Sunday school.
Inviolable?
Sacrosanct?
Numinous?
Sacred?
If this word’s really commonly used, you’d think that one of us would have been able to come up with it by now. 
From a review of a translation of the late 12th century Boethian Commentaries of Clarembald of Arras:…[S]cholastic theological argument need not be obscure. At certain places, Latin terms are preserved, and not fully explained, such as intellectibilitas, a term which the translators explain in the introduction refers “to a supra-rational power that infuses knowledge of divine things into the mind.” (xxii).
It may have been helpful to relate the term to intelligibilitas, explained by Thierry of Chartres not as intelligibility, but as intelligence, or a force of the soul understanding pure forms, in other words as a fully human, rational power. Whereas Peter Abelard coined the neologism scibilitas, to argue that this was an abstraction derived from scibilitasor knowable, Thierry of Chartres and Clarembald identify intellectibilitas or intelligibilitas as a capacity to understand pure forms, existing outside of matter. This is a very different thought world from that of Peter Abelard.
The translation can be recommended as a way of introducing students to a pattern of Christian Platonism, closer to that of Thierry of Chartres than to that of Hugh of St Victor.
“The only word for this is – transplendent. It’s transplendent!”
Sad, though, as well, as this was the first image I had of her after seeing her public humiliation-for-profit by Dr. Phil.
Who said that?