Question about "faith"

[Belacqua]

Has the word salad been settled yet? Honestly, it's probably a good read, just far too many pages to catch up on. I have faith in God. I have faith that this chair will hold me up when I sit on it. They are the same faith. I believe in God and I believe in my chair. I do not have absolute faith that all people are good all the time. I do have faith that most people can be good.

Why do you believe in your chair?  You have sufficient evidence to prove it exists, and nobody has a reason to doubt its existence.  Belief is not needed.

As far as I can see, the word "belief" has three main meanings, and they tend to get conflated in discussions like this one.

It can mean that we hold a thing to exist or hold that it's true. So "she believes in Santa Claus," or "I believe the world is round," falls in this category. This is for anything we hold to be true, not only things which are undemonstrated. "He believes in ghosts" is in this category, but also "I believe that dinosaurs were real." 

I don't think it's correct to say that belief is only for things which are not sufficiently demonstrated by evidence. It applies to anything we hold to be true, well-demonstrated or not.

"I believe in it" can also mean that we support or hope for something. So we can say "I believe in equal pay for women." In fact the world doesn't have equal pay for women, so we can't say we believe in it the way we believe in oxygen, or some other thing which is well-demonstrated to exist. We say we believe in it because we hope for it.

And third, if a friend is losing confidence before a difficult undertaking, we can say "I believe in you." This is not to reassure him that he exists. That's not in question. It means that we have confidence in him. 

Some people here are making belief/faith/trust into a question of God's existence -- the first type of belief I mention. Others, who believe in God, are using belief/faith/trust to refer to confidence, the third usage I describe. This is what tackattack means when he says he has faith/trust/confidence/belief in his chair. Its existence is not the issue.