My turn.
"
Belief: The fundamental positive cognitive attitude that commonly takes a proposition as its object. Most philosophers hold that propositional beliefs can be occurrent, in which case there is conscious assent to a proposition, or nonoccurrent, in which case a person has a disposition to assent to a proposition (such as 2 + 3 = 5) even though the person is not consciously thinking of that proposition.
Theologians distinguish belief that something is the case from belief in a person or ideal, as when a person believes in God or democracy. The latter seems closer to the biblical concept of faith. It seems clear, however, that belief in God is not possible without some propositional beliefs as well, since one could hardly believe in God if one did not believe that God existed or believe anything about God’s character."
-Evans, C. S. (2002). Dictionary of apologetics & philosophy of religion.
"Many spiritual seekers have legitimate questions concerning Christianity and need to pursue answers that will satisfy their heart and soul. Yet I think some seekers get to the point where they are subconsciously raising smoke screens to mask their deep-seated motivations for rejecting the faith." -Lee Strobbel
Now, I'm not saying that of you doseofreality but simply pointing out one example of why some people
choose not to believe.

.
And amongst those who do, their theology and understanding is often misguided and unexamined. They never challenge themselves, challenge doubts, and ask thoughtful questions. My belief is strengthened in times of adversity, tough questions, and contemplation... the very things that led you to dispose of yours.
There is a difference between us my friend and it's a four letter word: will. I apply it to my faith. You didn't.
Think of Abraham who experienced times of doubt, didn't always do the right thing, and had motives that weren't always pure. Yet, he is remembered as the "father of the faith."
Abraham made a choice to believe God and over time God gave him the gift of faith interacting with Abraham until he had all the experiential content and knowledge he needed to never doubt God again.
That is why Abraham is called the father of the faith.
One exercises their will to put their trust in Christ and God empowers them. Jesus says, "If a man chooses to do God's will, he will found out whether my teaching comes from God or whether I speak on my own" -John 7:17.
Will -->Faith-->Knowledge/Experience-->Belief. It's not for no reason that faith is always a verb in the Gospel of John (e.g. a direction of life that God begins validating).
Many smart people have exercised their will toward faith on the corroborative evidence that exists for God subsequently gaining the requisite knowledge
and experience from God resulting in absolute belief.
This why the Bible paints a picture of faith as an instrument. The imagery is that of saving faith appropriating Jesus Christ and everything he has to offer (Jn 11:25–26; 14:1; Acts 16:31; 1 Jn 3:23), the means by which a person is justified (Rom 3:28; Gal 2:16; 3:8, 24), sanctified (Acts 15:9; 26:18), adopted (Gal 3:26), and the action through which a person receives the righteousness of Christ (Rom 3:22; Phil 3:9).
The Bible is full of accounts of the faithful which show what genuine faith can lead to but so is our world today.

. Yet are there any heroes and heroines of the Bible without faith? No.
Even the great falling away from the faith foretold at the very end of this age that precedes the rise of the "son of perdition" (e.g. anti-Christ) and the tribulation that will follow before Christ's return at which Jesus Himself once wondered if any faith at all will remain when He returns (Luke 18:8) itself can strengthen one's faith as they observe the prophecy in action.
Meaning that faith can certainly grow stronger. Though the faith of some may be weak (e.g., Rom 14:1), there is always room for it to grow (Lk 17:5; 2 Cor 10:15; 2 Thess 1:3).
Even in small doses, genuine faith is potent stuff. This is not due to the power of the faith itself but to the power of the God in whom faith is placed as faith is an open door into a relationship with God (Acts 14:27).