Emotions are a wholly ineffective tool for determining what's true in reality.
Kinda but not totally? They're critical to decision making. I already stated that they "aren't a reliable way of evaluating the veracity of facts". But they are an essential tool for evaluating the importance, to you, of the facts in front of you. Example link. There are plenty of studies about this. To the degree that you're right, I already acknowledged it. To the degree that you're not right, you have confidence in science so a little google research will resolve the problem.
How is faith different than some vague emotional concept similar to hope and elevation?
I don't really consider any of those concepts to be vague. They are words, symbols with meaning. We need to share a common language to communicate effectively, so I'm good with dictionary definitions here. I'm not trying to force some made up personal definition on you because that would distort the conversation. I cited Hebrews already, the most common quicky definition for Western Christians. You can look up faith and hope in the dictionary, or elevation on wikipedia.
Here's a quick composite definition: Trust, hope and belief in an idea (God/Spirit/Brahman/Whatev) for which there is no proof, to the extent of motivating an allegiance to the idea (God/Spirit/Brahman/Whatev) that (allegedly) informs the actions and behavior of the believer.
Why is it important? Similar to the value of emotioins - waiting for absolute proof before you can act is just a formula for inaction.
Faith, as hope confirmed and sustained by elevation, can generally confer benefits on upon the faithful, whether the hoped for belief is true or not. Example link. Of course, it can also screw you over (as with "love" as mentioned in my post), which is why I emphasized that faith should be approached in an informed way, needing "to be harnessed in healthy and constructive ways."
I do not in any way advocate ignorance. But I think pretending faith is not a thing, or that it hasn't been studied, or that it can't be understood in healthy and constructive ways - pretending those things is just as ignorant as pretending faith is "a reliable way of evaluating the veracity of facts".
Isn't credulity part of the human condition? I read history and see quite a lot of it. How is faith different?
They're synonyms, with faith usually meant to convey the more positive aspects of moving forward with conviction in the absence of complete information because complete information is not readily available, and credulity usually meant to emphasize a wider tendency towards gullibility in all things without even caring to investigate information that is available. IMO, t's word choice to emphasize a positive or negative spin.
I AM trying to understand it. But that understanding seems to lead me to a place where it would be much better to not have anything to do with it at all.
Just an opinion, but I think the negative aspects of faith are driven by institutional and authoritarian demands that your faith conform to a set a predetermined conclusions that you haven't even explored yourself, and therefor can't really exercise faith in. Organized religion tends to tell you that you need to have faith, and then immediately dictate the perameters of it, preventing the process of discovery that lets you find what works in a healthy positive way for you. It's a great starting point, but a horrible finish line.
I'm not trying to prescribe any particular creed. I'm just saying that approaching human spirituality has value. You see a lot of thinking religionists moving from denominational Christianity to variations on secular Buddhism for just this reason - they find themselves unable to conform to established creeds but still find value in faith. There's something there, inside most people if not without, and it's healthy to explore that aspect of yourself in constructive ways. Ignore it if you want, but don't pretend people who try to explore it are necessarily ignorant. Usually the opposite is true - whether diving in without thinking for yourself, or shoving it aside with disregard, both approaches probably fosters more ignorance than intelligence.
Ignorance is not a pathway to truth. Faith is, or can be, a pathway to truths about the self and its relation to the wider world, that are largely inaccessible to science. If you want, apply the scientific method to your personal introspection, but I have a feeling that research grants for it aren't going to be readily available.