Doubt can lead to unbelief but it need not lead to it.
I think it is helpful to make a distinction between KNOWLEDGE and RELIANCE/faith/trust. They are related, often, but not at all identical.
Faith can be a noun (in which case it applies to the subject of our faith) or as a verb (in which case it applies to the trust/reliance in that subject).
I'll address it from the standpoint of the verb since that's the use we commonly use.
"Faith" = to trust, to rely. Especially trust and reliance in something that cannot be empirically proven. Theologically, to trust and rely on God. It does not mean (at least not primarily or exclusively) to understand, to comprehend, to embrace as factual.
When I was a kid, I had surgery (long story, doesn't matter). Anyway, I was just old enough to know I could die - and what that meant. I actually was okay with that. It had very little to do with heaven (a concept not yet in my heart or head) but with 1 John 4:8, "We rely on the love of God, because God is love."
I remember meeting the surgeon in the hospital - and that he kept calling me by the wrong name (Joe, I think). I realized, he doesn't know me - much less love me or even care about me. That was powerful. I remember being moved onto the cold, hard table with the huge light above me - although by this time I was already very sleepy - fighting that as best I could.
I didn't know anything about the surgery, I didn't know anything about this surgeon, and clearly he knew nothing about me (not even my name) - or any of the rest of the staff involved in all this. And yet, I entrusted my life. Willingly. And I so remember being okay with that. I so remember thinking: no matter what, it's okay, God loves me... His love will triumph
no matter what happens.
While my reliance was active on my part (I placed my life in their hands), there were no "works" on my part involved. There was no "obedience" other than I laid limp and allowed to happen whatever happened. There was little to know knowledge on my part. None of that mattered.
Another illustration...
I know how planes fly; I understand the principles involved (I have a Ph.D. in physics). Still, whenever I board one of those HUGE planes, I am amazed. They are so big and heavy! And inside, they are STUFFED with overweight Americans (probably more so than the engineers planned for), and under them, all their luggage - too much. It's always the same. I look at those wings and that curvature and think, "no way!" And, of course, I don't know the pilot and he doesn't know me (or care). I don't know the flight plan or the weather report. I don't know the mechanics or their reports or when this plane was last overhauled. In fact, I know NOTHING about this particular plan or crew or flight. And I realize that when a plane stops working at 40K feet, well, it means we'll all be meeting Jesus. While the ODDS of that are very small, that means little for this particular flight - this could be that 1% (or whatever). It bothers me not. I board the plane. And as it takes off, as it's going down the runway, I hope to be able to see the wings and sit (passively!) in awe of it all, and then, surprisingly soon, the wheels chirp, and the plane rises - gloriously, and Hawaii is just 5 hours away.
Faith and Knowledge certainly have a relationship, but it's not a causitive or mechanical one, but rather a relational one. See my two illustrations above.
To insist that faith is the RESULT of knowledge is to deny that those below a certain IQ or age are capable of faith and therefore of salvation. And, IMO, undermines the very nature of faith which is to rest, rely, trust.
I am well aware that I can't "prove" much of anything that is in my heart. Actually, I "understand" probably LESS today than I did years ago (I was my smartest when I was a sophomore in college, lol), more aware of the questions than the answers I have, more aware of mystery. It hasn't impacted my faith at all (if anything, it's increased it).
As noted earlier, directly to the thread, no.... I never forget that God LOVES me. It is foundational to my faith and life and being. Yes, the fallen world is full of bad, and that will impact us, but that's not the focus of my life or soul - God is. God's heart - His unconditional love, mercy - are the constant, the certainty, the anchor... the ultimate Reality. God is love.
- Josiah