It can be easy to unintentionally jump between different definitions of a word in conversation.
This happens often with faith.
Faith can mean belief or trust, but the reasons someone should believe or trust something are obvious: You believe what you’ve been convinced of; you trust what’s proven trustworthy.
The only thing that spiritual or religious faith has in common with belief and trust is that none of the three are a choice.
So why should someone have (spiritual or religious) faith?
At its core, this kind of faith is simply insight for potential.
We all have hopes and intuitions about how we wish things could or should be. Faith occurs whenever we see that these internal yearnings or ideals could potentially come true.
What kind of person do you think you should be? What value(s) do you wish to bring to the world? Again, faith happens when these desires drop from being mere hopes to actual beliefs about a real possible future.
Faith gives evidence to our hopes. In other words, when we see our hopes connect somehow to experience, this reveals or proves (confirms) that the desired outcome could really happen.
So, why am I using such abstract language to speak of faith, leaving out anything close to doctrinal specifics?
The stories that account for why faith works (and for why . . . everything else) are a separate discussion. In my experience, faith works regardless of the “why”—regardless of the interpretation or accounting narrative given to explain and define its parameters.