You think I'm wrong, and you appear to think the reasons I am wrong are obvious.

Well, you see, two comments ago you were telling me I was wrong for obvious reasons. You told me that I don't understand and if I understood I wouldn't think X, when in fact I do not think X.

I will not presume to guess how subtle the reasons are for which you are wrong. But you assuredly told me, with every sign of great confidence, that I think something I don't in fact think. You are now doubling down (in that you continue to insist that I am wrong) while backing off (by now saying you think I'm subtly wrong, where what you were accusing me of before was in no way subtle). So I think you may if you please claim either intellectual or moral high ground here -- but not both.

Assume, for a moment, that I, also, am not an idiot.

I do, I assure you.

the fact that you stopped being a Christian might suggest you have a different relationship to faith than those who do not.

No shit, Sherlock. On the other hand, (1) it's not so clear that it means I had a different relationship to faith from that of other Christians, (2) the fact that I lived as a Christian among Christians for decades and remain married to one and friends with plenty more means that I'm not exactly starved of opportunities to discover or remind myself how they think, and (3) you are still writing as if all religious people think and feel the same way about these things, which is demonstrably false.

To a religious person, faith is about them proving themselves to God; evidence or non-evidence of God doesn't actually enter into it. [...] Faith isn't trusting God, it's living up to God's trust in them.

The New Testament's use of phrases like "faith of X" is notoriously ambiguous, and indeed "faith" can mean "faithfulness" in the sense of trustworthiness rather than anything to do with belief. (And, I think more often, "trusting a person" rather than anything to do with factual belief.) However, I think you are simply factually wrong if you are claiming that most use of the word "faith" by religious people in general, or Christians in particular, has that meaning; and wronger than wrong if you are claiming that "faith" can't reasonably be used to denote something closely akin to belief, which I think is what would need to be true to invalidate the suggestion that you use the word "faith" rather than "belief" to describe the particular sort of thing you feel more positive about these days than you used to.

(I remark that earlier in the thread you were clearly happy to use the word "faith" to describe a particular kind of belief or something very closely akin thereto; taking "faith" to mean anything like "trustworthiness" makes total nonsense of the comment I just linked to.)

Now, of course you may quite reasonably feel that my opinion about how Christians use the word "faith" is of no value since I am not a Christian. So let me pull a few books off my shelves and see what they say about it. (No cherry-picking; I just took the first books I found that looked like they might have something to say on the point.)

• A concise dictionary of theology by O'Collins and Farruga. (Roman Catholic; the authors are Jesuits.) Entry headed "Faith": "The objective, revealed truth believed in (fides quae) or the subjective personal commitment to God (fides qua)." (There's more but none of it involves the idea of faith as trustworthiness.)
• The Christian theology reader by McGrath. (Anglican, I think with evangelical leanings.) Three index entries under "faith, nature of".
  • John Calvin. "Now we shall have a right definition of faith if we say that it is a steady and certain knowledge of the divine benevolence towards us, which is founded upon the truth of the gracious promise of God in Christ, and is both revealed to our minds and sealed in our hearts by the Holy Spirit." (There's more, but it's all about belief-that founded in trust-in and experience-of.)
  • Martin Luther. "In the twelfth place, faith does not merely mean that the soul realizes that the divine word is full of all grace, free and holy; it also unites the soul with Christ, as a bride is united with her bridegroom." (There's more, expanding on that theme of unitedness. Luther's writing here about the effects of faith rather than its definition.)
  • John Calvin again. "We make the foundation of faith the gracious promise, because faith properly consists of this. [Faith] is certain that God is true in everything ..." (Again, there's plenty more; Calvin wants to define "faith" to be something more than mere belief (cf. that famous bit about demons in the letter of James) but it's clear that it's a particular sort of belief, under particular circumstances, that he calls faith.)
• A new catechism: Catholic faith for adults by various RC institutions in the Netherlands. (Roman Catholic, with liberal leanings.) This uses "faith" to mean many different things in the space of a few pages, and it's not always clear what's intended to define and what merely to describe. Here are some excerpts from the section headed "Faith" about half way through. "Faith is the gift of the Spirit which enables us to give ourselves entirely to him who is greater than we, and to accept his message. [...] Faith is a leap, but not an irresponsible one. It is justified by the leap itself. [...] Faith means partaking in God's life. [...] Faith is something which we have in common. We believe together. -- We also believe for others. This is the only answer when we ask ourselves why we believe and others do not. [...] Faith means to say Yes to God's revelation. [...] Is faith surer than science? It has a certainty of a different sort. It may be affirmed that the assent of faith is attached to the most profound of our faculties." Etc., etc., etc. Reading the whole thing (which includes e.g. a lengthy section on the relationship between faith and doubt) I think they're taking something-like-belief as the primary meaning and saying that it's a consequence of God's grace and has all sorts of other things as consequences.

That'll do for now. The point is just this: These books -- written by Christians, mostly for Christians -- are utterly irreconcilable with the claim that "faith" in the Christian context mostly means something like trustworthiness. They mostly take it to mean a kind of belief or a kind of trust or both. Of course they also claim that it's a belief-and/or-trust with a divine origin and all sorts of marvellous consequences, and that it should have consequences for how one lives; but they do not appear to agree at all with your suggestion that it's a misuse to use "faith" to denote a kind of belief.

(They do, to be sure, make it clear that for them "faith" is not simply a synonym for "belief", but I never said or suggested or thought that it is. I mention this merely because some of what you've written seems to suggest that you think I do think that.)