Responding to the OP, I wasn't brought up in church, my father was a maths professor so I lived and breathed critical/logical argument from the earliest days, and in my teens I would say I straddled the agnostic/atheist boundary. If I was honest I would say "agnostic" as I genuinely didn't know if there was a God, if I wanted to appear a bit edgy and cool I would say "atheist".
But I had a very close friend who was a Christian and, as folk in their late teens will do with their close friends, we talked about all sorts of things, including the purpose of life and whether there was anything more to it that just what we saw in front of us. I recognised that my agnostic/atheist perspective was woefully inadequate on addressing questions which I saw were vitally important in how I was going to live my life and how I viewed the world. It also wasn't a purely academic question - in the sixth form I was in I noticed that the small number of committed Christians (my friend included) had a qualitative difference to them - less petty, more open-hearted and open-minded, seemed to be a bit more "together" in themselves, a quality of being at peace with things relative to the rest of us. And the particular Christians I knew weren't judgemental, quite the reverse - they seemed to move easily between the different cliques that the college tended to divide itself up into and were very accepting of the diversity of people there.
So I decided to take a chance and see if the Christian faith could work for me, which I did when I went off to university. I saw it as an experiment (I was doing a science degree, after all) that if it worked I would have gained something very precious, and if it didn't then I would lose nothing, except for a bit of time while I tried to work it out. And over 20 years later I am still here, as committed as ever. Having completed my psychology BSc I later went on to study theology in a secular university context, so I believe I can say that I have thoroughly thought through what I believe. With my background and experience I do find it a bit trying when people on internet forums say "Christians believe what they believe because they do so unquestioningly, they uncritically accept what they are told". Absolutely not in my case.
I was pleased when I heard Prof. Alister McGrath speaking a few years ago about his journey to faith. He had been a committed atheist, and was a very serious scientist, studying for a DPhil in Molecular Biophysics at Oxford. But he began to see that Christian narratives about how the world is gave answers to his questions that were stronger than the other narratives that he had come across, including those from scientific materialism. He looked into Christianity with the sceptical mind of a trained scientist and found a coherent explanation of the world and how to live a meaningful life, and he converted to Christianity because the explanations it offered he found more compelling than any others. While I am not as bright as Prof. McGrath, I could very much empathise with how he had found faith.