Hola Esteban:
You bring up a great point, and one that has baffled me for my entire 30 years of married life, probably only because I have never sat down and considered it from a purely non-judgemental point of view.
My wife has always had a great deal of faith. I cannot really describe her as a typical Christian, although her childhood religious background is Protestant but basically unchurched.
Anyway, my wife has had to live for 30 years with what most everyone we know characterizes as an atheist, and in truth, I have not done a whole hell of a lot to convince them otherwise.
My wife does, however, see right-wing, conservative Christian political activists as "the enemy," and doesn't have much nice to say about folks who wear their religion on their sleaves or around their necks.
The point is, she still has loads of "faith" and prays regularly, mostly I think for God to give her the strength to live with what she has to live through as a mother, wife, and professional woman in a man's world.
As far as biblical scholastics, she has a decent memory of bible stories she heard as a young person, but occasionally combines them into even more of a fable than they were to begin with. She gets extremely pissed off when I correct her, say for her expressed notion the other day that Magdalene was a prostitute, for example. I've never seen her read the Bible, and she possitively cannot stand it when I use the Bible for a reference document. I don't think she could really care less whether the Book is inerrant, errant, partially wrong, totally true, or whatever.
Basically, I think she believes Jesus walked the earth, that he taught good things, and that there is a God to whom she regularly prays for strength. Bottom line: my wife has a great deal of faith in her personal system of belief but rarely makes an issue of it or comments about it.
However, every time some great fortunate thing happens to us, or each time we successfully weather another one of our seemingly endless traumatic events concerning our children or other family members, she reminds me of her "faith" and chastises me with, "and I never want to ever hear you say again that there is no god ... you better think about that." BTW, another little quirk, she does not necessarily believe in "fate" or "chance" but rather favors mathmatical probability or some kind of spiritual amortization charts.
Anyway, mi amigo, I think your comment, "so if these people, countless Christians included, can accept that the Bible doesn't have to be taken literally in this case, why do you assume that Biblical inerrancy is necessary for faith" is very pertinent to the way a vast majority of folks, at least in this country, believe in and practice their "faith."
Vaya con Dios, Homs.