Belief without Verification or Certainty

[Deesse23]

Because her confidence could affect the outcome of the interview.

Yes, and someone should not conflate this "confidence" (in oneself for example) which actually can effect the outcome, with the classic "belief in" stuff. Believing in stuff will usually not effect the outcome, as in the existence of god or if the bus will arrive in 5 minutes.

Those arent the same.

No one denies that unverified belief can be bad. But I find it interesting that it can be good in certain cases.

No one denies that playing roulette can make you lose money. But I find it interesting that gambling can get you to make you money in certain cases
The problem with this thinking is: Unverified belief does not consistently lead you to anything (good, or true), unlike verified belief

Let's talk about how much we want to willfully include unverified belief in our lives.

Ok
Would you like to believe you can jump down the Empire State Building? Ill give you a motivation coach, who will teach you to be more confident in yourself (see below).
Would you jump, ever? You cant know unless you tried, right?

In a thought experiment constructed by William James, we are asked to consider a mountain climber who dodges an avalanche. He finds himself stuck in a spot where he must jump across a chasm in order to survive. Physically, it is possible for the climber to make the jump, but it is by no means certain. We can imagine a scenario where the climber has the belief that he can make the jump and this belief makes him surer of foot and influences the outcome positively. In that case, he makes the jump. And he can look back and say, "My belief that I could make the jump was correct." But what if he does not have the belief that he can make the jump? Let's say he was unsure he could make it. Let's imagine that, without the boost in confidence that the belief that he could make the jump bestowed, he didn't quite make the jump. As he falls to his death, he could similarly think, "I was correct to not have the belief that I could make the jump."

Again: Confidence led to better performance. He didnt make the jump because he believed (hard enough). Belief didnt make it true. He made it because he performed better with confidence.