I was raised Christian, but have slowly became "not Christian" as I've aged. My family though has never really been evangelical Christians.
I wanted to comment on this choice though:
"I had to check a religion box, and Christianity was the best choice."
It made me think about why all my paperwork when I enlisted in the Navy said "Catholic". The recruiter apparently checked that box for me because my mother had mentioned to him that "we" were Catholic (I was never really Catholic, although I do know a good deal about the beliefs). I guess it ties into the "born Christian" thing as well. There are still plenty of people who will state their religion as their family's religion, even if they know they are different. Now, some parents don't necessarily realize that their children have different beliefs than they do (I think my mother just considered Methodist, which was closer to what I was raised as and what I probably would have considered myself at the time had I really thought to label myself, was acceptable enough along with the teachings from her and my grandmother to consider us all Catholic, along with the fact that we were all baptized at birth).