“We ought always to thank God for you, brothers, and rightly so, because your faith is growing more and more, and the love every one of you has for each other is increasing.”
A lot of people, even Christians, think that faith is blind trust, and for our faith to grow we just need to learn how to step off more cliffs in the dark. But that’s not what faith is. Faith is more than hope, and it’s more than spiritual optimism. Faith is knowledge, pure and simple. Every time I sit in a chair, turn a door knob, or turn the key in my car, I am living by faith. I don’t KNOW that the chair will hold me, to door will open, or the car will start. But I have past history that chairs hold people, knobs open doors, and keys start cars. Therefore faith is not a leap in the dark, but an assumption of truth based on enough evidence to make it reasonable for me to make that assumption. My faith is God is based on evidence—the evidence of Scripture, of other people’s lives, and of my own life.
How can such faith increase? The point is that the farther we go in the Christian life, the more we see and understand of how things work, how life works, and how God works. Since faith is an assumption of truth, the more I learn, the more assumptions of truth I can make, and the more I can live by faith—knowledge of how God works regardless of what I can actually see.
So for my faith to grow more and more doesn’t mean I get better at blind faith and trusting God; it means I know more because I see more, and therefore I trust God more in the ways that are reasonable assumptions of truth.