Faith is life-changing; life-altering. The ground of life shifts for the good when faith becomes authentic in its application to ones daily movement.
While it admittedly is invisible, it is surely a legitimate concept within the human framework. Activity is affected by either its presence or its absence. Faith is the assurance of things hoped for, the conviction of things not seen, wrote the Hebrew writer.
So how does one function differently by possessing faith compared to not having it? One of faith moves about believing as fact what isn't seen at the moment. Until this action begins to work, faith could merely be a fictional Sunday School concept. But faith works; it is active and makes a difference for the one believing.
Let's say two people don't get along. A hope-so faith will wait to see if things work out; but will not operate as such until it happens. Faith sees it has already happened and those who choose to believe find their talk and their walk to be one of resolution...even if only one believes it. God must have a believer in the mix.
This is a tough concept for us because we don't care for the name-it and claim-it philosophy. I hedge on such myself. Yet, this is where we mistakenly toss too much from the bath water. We are to believe what we can't see. We are to believe what isn't (yet) as is. We are not to use such a doctrine flim-flamically. But I believe faith is bigger and stronger and wider reaching than what we tend to accept.
We believe un-things into existence. This is God's teaching in Romans 4:17ff. It isn't that we possess a faith in our faith. We believe God can do what can't be done. He measures much by our faith.
I think faith makes a big difference. Yet, we are guilty of practicing more of tossing-the-dice doctrine mixing crossing one's fingers and wishful thinking. Faith takes work, imagination, and conviction....in the talent and skill of God. He can. He is able. And...He is ever on the watch to find those who believe Him.
Faith isn't one of the five steps. It is to be a new way of life.