This post will be probably a mess; it's 1:03 AM and I have church in the morning.
I was born into a Christian family. Mom was raised Lutheran, Dad was raised Baptist. My family attended a Methodist church for the majority of my childhood, and when it came time for "confirmation" (it's basically middle-school age, you go through a bunch of classes and then make a faith statement in front of your congregation affirming your faith and stuff) my family moved us to a Lutheran church at my mom's prodding. I was brought up as a pretty serious Christian, went to church almost every week, (including extra Lenten services, holidays, etc) but around the age of 10 I had some doubts. I started to notice that I didn't feel God's presence in my life, like I was supposed to, and I went around telling people I didn't believe in God, mostly to be edgy and cool and rebellious. I think deep down though at the time the habits were far enough ingrained into me that I probably still believed, but it was nonetheless the first time I'm aware that I started to doubt the religion I was raised in. Around middle school, when I started having to go to confirmation classes, my faith grew stronger. This was likely due to the community surrounding and supporting me in my "faith journey," for lack of a better term. Went through those classes mostly without a hitch, for me they were more of a social event than anything, because they were usually fun and had snacks and activities and plenty of things that were appealing to me at that age. I made a couple strong friendships in my little group, and I also attended evening youth group events that were also fun (mostly non-religious, we often just played games and didn't focus much on spirituality or religion much.) My faith peaked in 9th grade or so, when I was finally getting to be mature enough to understand the positive parts of Christianity, to keep in mind the context of the negative parts, and to wholly "devote my life to Christ." I started out that last year of confirmation a true believer, but public school and other viewpoints and just a general popular and public disregard for the virtue of religion started to tear me away from it and restored some of my doubts I had stuffed away for several years. I still considered myself a believer, I guess, but by the time I had made it to 10th grade (age 15,) when it was time for me to actually commit to being confirmed, I panicked. I wasn't ready to commit to affirming my faith in front of the congregation and everyone, but to refuse to do so would be extremely taboo to my entire family and I wasn't about to deal with that, so I just went along with it and faked it even though I was still unsure of what I believed. Shortly afterward I considered myself agnostic, but I still practiced going to church occasionally with my parents and attending the fun youth functions that still appealed to me. At the end of my senior year of high school (age 18) my church did a final confirmation type thing to bless us after graduating high school, sort of as a reminder that we had pledged our devotion to the church and that we shouldn't forget to come back once in a while. Since then (2 years later, I'm 20 now) I have rarely attended church, I still don't feel much at all in the way of spirituality and my studies have led me to mostly believe there is no God, but I don't think there is any way of anyone knowing for certain. I consider myself an agnostic, for that reason. So basically my whole life I've been dancing around the spectrum of serious hardcore evangelical Lutheran Christian to mostly atheist agnostic, but I think for the rest of my life I'll probably hover around the latter end. Since I met my boyfriend, who was raised in a very traditional Orthodox Christian family and is now essentially atheist, I've learned to appreciate the finer parts of Christianity, namely the history, the literature, the art, and the scholarly leanings of much of it, but to me the core substance is basically completely gone. I go to church when I can't avoid it or feel guilty enough for disappointing my family (that's what tomorrow's deal is) but if I had my choice I probably wouldn't attend much in the future, if at all.
TL;DR: Raised Lutheran Christian, now basically agnostic atheist.