I was born into a Christian family (Presbeterian). My father is still a member of the church but somewhat lapsed now and goes along with my mother to make her happy. My mother is a church warden, very much a believer, and she and I agreed long ago not to discuss religion much. She knows I'm an atheist and still sometimes sends me things or articles hoping it will make me "see the light" and turn to Jesus etc. My sister is a believer, not as hardcore as my mom. My grandmother on my father's side was very very hardcore fundamentalist christian, to the point that we let her live on and pass away never knowing I was an atheist, because it would have made her very worrisome and upset.
I myself went to church as a child, enjoyed the social aspects, went along with the rituals, but never truly believed. I remember the day when I was 12 or so when I realized that the people there actually BELIEVED this stuff and it wasn't all just theatre and make believe to them.