I grew up Christian (of sorts) and drifted away from the belief. Like you write, it felt like a convenient lie. I was convinced it was a myth invented by humans to bring themselves comfort. Observing human suffering seemed to me to be
proof of no God. I heard of the Buddha who declared both that there was no creator God and that life was suffering, and based on what I had seen of poverty, disease, and war this seemed to be the case. For me, I saw my rejection of Christian claims as a very element of my personal need for 'capital-T truth'. I embraced that motto of Rousseau and Juvenal and began studying every -ism and theory apart from Christianity.
Eventually, I would run into a philosophy B.A. who was also a Christian. I constantly pressed them for justification of their belief and their main response was this quote by Kierkegaard: "If there were no eternal consciousness in a man, if at the bottom of everything there were only a wild ferment, a power that twisting in dark passions produced everything great or inconsequential; if an unfathomable, insatiable emptiness lay hid beneath everything, what would life be but despair?" -- If there were no God, life would be despair (and Siddhartha would be right) so we believe. This line of thought upset me. What I wanted was to know what was actually the case, how the world actually was and not how we might like it to be. Truth at any cost no matter how inconvenient, bewildering, or painful.
I studied Buddhism and Eastern philosophies (which are basically methods of coming to terms with and accepting nihilism). But I retained an idea that human suffering was bad and humans somehow had value. Reading Hume is what changed me. Unless an outside rubric existed that would declare human suffering bad, human suffering never actually had been bad at all. But I believed internally stronger than any other belief that somehow it truly was bad and this instinct seemed to be a self-evident truth. What Hume shows is that this instinct that we feel is either placed in us in relation to a Supreme Being and its existence functions as a unit of evidence called natural revelation or it is a strange delusion we invent and we delude ourselves that human suffering matters.
A liberating realisation was that, in light of this, if the second scenario were the case, it was also not morally 'wrong' anytime humans proclaimed suffering was wrong, one would have merely paid the universe a compliment it would not have deserved. If the unempirical does not exist, then proclaiming it does is not wrong. In the words of philosopher Thomas Nagel: "If sub specie aeternitatis there is no reason to believe that anything matters, then that does not matter either".
As far as quitting the search and holding logically untenable positions, I suggest this remark by Walker Percy: "This life is too much trouble, far too strange, to arrive at the end of it and then to be asked what you make of it and have to answer “Scientific humanism.” That won’t do. A poor show. Life is a mystery, love is a delight. Therefore I take it as axiomatic that one should settle for nothing less than the infinite mystery and the infinite delight, i.e., God. In fact I demand it. I refuse to settle for anything less. I don’t see why anyone should settle for less than Jacob, who actually grabbed aholt of God and would not let go until God identified himself and blessed him." He portrays a worldview known as the supernatural existential, desiderium naturale, or Man as Wayfarer in his book The Moviegoer explained here: http://liamk.org/moviegoer/