What is a less offensive term for "Christian mythology" that still implies it's non-empirical?

I'm trying to find an alternative term for "Christian mythology" that characterizes it as non-empirical, but isn't quite so caustic towards those sympathetic to Christian beliefs.

I've considered "cult mythology", since it's less specific, but that seems even more offensive. I've also considered just "mythology", but I need to make a distinction between works which were never intended to be taken seriously, and works that were. This last part is key, since the focus of my debate is cognitive dissonance.

“Faith-based beliefs/belief systems” is used and contrasted with “science/evidence-based beliefs/belief systems” in the linked ‘Science 2.0’ article:

Belief systems are the stories we tell ourselves to define our personal sense of "reality". Every human being has a belief system that they utilize, and it is through this mechanism that we individually, "make sense" of the world around us.

There are two forms such belief systems can take; evidence-based or faith-based.

You can simply refer to them as religious beliefs. No need for "system" or "faith-based", as they might or might not be systematized, and faith-based is redundant. "Cult mythology" is likely to be perceived as derogatory by some.

Also, you're misusing the word seriously. You probably mean literally.

...fictional works which were never intended to be taken seriously...

You could use 'theist doctrine'

Theist - noun

1 - a person who believes in the doctrine of theism

2 - a person who believes in the existence of God or gods

www.dictionary.com

Doctrine - noun

1 - a particular principle, position, or policy taught or advocated, as of a religion or government: Catholic doctrines; the Monroe Doctrine.

2 - something that is taught; teachings collectively: religious doctrine.

3 - a body or system of teachings relating to a particular subject: the doctrine of the Catholic Church.

www.dictionary.com

If you're speaking specifically of the Biblical account of creation, I would use the term "Judeo-Christian creation story." The term "creation story" contextualizes it in the general category of myths about the origins of the world, but without using the loaded term "mythology." Even many believers don't take the Creation account as literal, so you're being more inclusive of those in that category by using this term.

If you're characterizing the entire range of religious belief as mythology, then why bother soft-pedalling it? In that case, those who aren't receptive to your point of view are probably at least perceptive enough to pick up on your attitude, no matter how you term it. With that said, PapaPoule's "belief system" is probably the most neutral, respectful term to use in that case, that still implies no endorsement of said belief system.

(As a bit of unasked-for advice, if you do want to actually reach people who don't already agree with you, you're probably better off with one targeted example, rather than a blanket dismissal.)

Officially it would be legend, but I don't think that's what you aim at. I'd say biblical mythology if I were you. Maybe even better would be to note in the beginning that you’re an atheist and then just refer to it as biblical events. Otherwise, people might still feel attacked (at least I would as a Christian) and stop reasoning normally.

Biblical mythology is the term used by Jean-Marie Husser in Dreams and Dream Narratives in the Biblical World:

The diversity of these references, drawing on Greek, Persian, Mesopotamian, and biblical mythology and historiography and the subtlety with which they blend and combine, speaks eloquently of the art and erudition of their authors.