I can sum it up with a quote:
"Doubt isn't the opposite of faith; it is an element of faith." - Paul Tillich
My doubt is, paradoxically, why I have faith. It is the overcoming of this doubt that fuels me. It is me refusing to surrender, so to speak, to existential despair. It is the reason why I can empathize with unbelievers of any sort, rather than what others, say in the OT section, who just flame you for having the hard duty of actually thinking, unlike them.
Nothing makes me more angrier than those Christians who ask you to surrender your critical thinking in order to live by their own version of a "Gospel" which has no correlation to the human situation. The real Gospel is one that both shows the greatness of man and the despair of man; they remove both.