If the truth of Exodus doesn’t matter, why do you spend time presenting your argument against it? As your first and only example?
There are two kinds of belief: belief in the fact of a thing, and belief in the ethos of a thing.
For example, even the demons of hell believe in the fact of Christ’s divinity—what they lack is a belief in the ethos of it. The latter position motivates them to lie about the former.
It's a good example that encompasses both the mythology aspect of the Old Testament and a lack of historical and archaeological evidence. Beliefs don't really affect facts. Something is fact regardless of whether people believe it or not.