I suppose I can chime in on this.
I grew up in a Christian home as well. My father was a pastor, and my mother taught the children's choir for many years. I knew the right answers. I knew how I was "supposed" to act, and I even did so most of the time, church or not ... and I did it for one reason:
I felt like I was supposed to.
Truth be told, I didn't believe in ANY God at all, or any non-physical reality for that matter. I couldn't tell many people this, of course, because my dad was "the pastor," and if it got back to people in the church, it would (unjustly, I might add) reflect poorly on my dad in their eyes. In my mind, whether I believed or not, I had to act like it, because I loved my father, and I would NEVER want to see him criticized or defamed because I happened to not believe what he did. Still, though, it gnawed at me incessantly. I would ask questions in Sunday school or even to some of the pastors, and I always got quaint, token, cop-out answers (such as the one mentioned in the original post, which I got several times).
I went to college and I fell in love with philosophy ... metaphysics. I LOVED the notion that truth could exist apart from what could be observed physically, but instead be observed reasonably. I began to get militant about it, and I found a nice, anonymous outlet for it: teh interwebz.
I went on a particular message board (called NationStates) and I would intentionally search out Christians, well-educated or not, and I would argue with them. I never got upset. I never called names. I tried to remain respectful of the person with whom I was arguing. The truth is, I wasn't looking to argue for argument's sake. However, I wanted to find someone who I felt could hold their own in an academic forum, and I wanted to see holes punched in it. In retrospect, a message board probably wasn't the best, but the logic I saw there was head-and-shoulders above what I saw on the Huddle (no offense, guys). I never came across anything that wasn't without major problems or appeals to authorities I didn't accept (an appeal to a supernatural authority over natural law, for example, was logically possible, but I had no reason to start believing it: Occam's Razor, if you will).
I decided to go to college and major in religion, thinking I'd (a) come across the best defense of religion from people with Doctorates in it, and (b) if I could put to rest the best defense that religion had to offer, there would be no doubt in my mind that I was right.
For the first semester, things were fine. I would occasionally argue in class, though I had to admit, even at the time, that the professors sometimes provided fantastic, logical defenses for a certain belief. I at least developed a healthy respect for them, as they were the first people I'd ever heard that seemed like they could indeed hold their own in academia.
However, because my purpose there wasn't necessarily to get good grades, they suffered a bit, and I was assigned an academic mentor. He was one of the professors from the Religious Studies department, but he was also the Dean of Students and the Vice President of Academic Affairs. I was a little surprised that someone with so many hats had time to meet with a student every week.
In any case, I did meet with him every week, but I found myself talking more about religion and faith than about my academics, though they did go up. At the end of the semester, I had found that I was enjoying talking to him. He respected my view, and he handled my questions with genuine care, not with trite little responses, but with well-thought-out responses that provoked me to think. It was so enjoyable that I found myself looking forward to Wednesday nights, when he and I would meet.
Over the final two years of my college, I continued to meet with him. By the last semester of my senior year, I found that our discussions had made sense, and that over time, I had come to believe not only that a God-serving worldview was correct, but that I had somewhere along the line accepted much of the Bible as truth (at least, in the ways it is intended to be) and that I was a Christian. Not because I had been told so since I was little or because I wanted some mythical reason to believe, but because over the course of three years, I had come to be CONVINCED that there was a logical, rational reason for God's existence, and that the reasons for believing such were good reasons.
I don't know when it happened. It wasn't some grandiose emotional experience or instant faith-filled inspiration. It was over the course of several years, and just somehow during that time, I had come to be a "Christian."
I don't believe it's "just faith." That was one of the big cop-out answers I'd had from one of the pastors at my old church. I am more of the persuasion shared with an old friend of mine, a pastor from Warsaw, Indiana. His name is Kondo Simfukwe. He borrows shamelessly from Greek philosophy, and doing so, he says:
The unexamined life is ... often referred to as 'faith' by many Christians.
The truth is, I am only a Christian today because I was engaged with the validity of it over time, through genuine relationship, and on terms I accepted. He didn't spout the Bible to me, or any Josh McDowell or Lee Strobel. He used people like Albert Camus, Edmund Husserl, and even Carl Sagan. Then he showed that he could actually reason for himself in our discussions. THAT was what was so refreshing to me. No regurgitating anything from Answers In Genesis (in fact, he wasn't even a young-earth creationist). Answers that showed he had been thoughtful on the same questions I was asking ... and had refused to accept trite, Sunday-school-esque answers.
That man was Dr. David Plaster. His character was almost irreproachable. His love for learning was undeniable (the man spoke 7 languages fluently, for example). His kindness was unusual. He was, in my opinion, the perfect example of who a person should be. Hard working, always learning, and showing an abnormal understanding and love for others ... all because it was his duty as a human being.
Dr. Plaster left this world in March of 2010. I had a really rough time, and I attended his funeral in Columbus, where he had been the pastor for the Columbus Grace Brethren Church for about a year (after he left the college). He was an amazing man, and I owe much of my worldview to him. Ultimately, God has really helped me believe, resolutely, what I do. But God used him to reach me, and Dr. Plaster did his work well.
I have no doubt that upon passing away, he was greeted by the words "Well done, my good and faithful servant." I miss him, and I try to carry on in a way that would make him proud, which means that whatever truth is, I should pursue it. However, he also showed me that a strong, thoughtful, intellectual mind can arrive at Christ-centered worldview.
Sorry that was so long, and I'm sure at least one of you will give the stereotypical "tl:dr" response (Prick!

). I just thought it an appropriate time to share my story.