I live in Glasgow and in my street there are Protestants, Catholics, Muslims, Hindus and atheists as far as I know. At my last church (baptist) we had friends who had been Catholic, Muslim and Hindu but were now Protestant Christians. In our current (also baptist) church we have friends from Africa who used to follow traditional tribal religion. It's just not true that people don't change!
I was christened in the Church of Scotland but we didn't go to church regularly until I was 12. Attended the CofS then, something "clicked" for me when I was 16, I stopped going because my parents wanted me to, and started going because I wanted to. After a rather wild first year at uni I decided I'd go back to church, and started going to CU at uni, where I met my now DH.
We went to an Episcopalian church, very large, students, lively, and continued to go to the Episcopal church when we moved to a rural location, though it couldn't have been more different - small and traditional, but very friendly.
By the time we had dc we decided not to get them baptised, as we wanted it to be their decision when they were older. We've both always been involved in church and para-church groups, like bible study groups, children's work, youth groups, homeless shelters, work with refugees.
7 years ago now we moved to Glasgow where dh and I both undertook degrees in Theology, after a lot of discussion he resigned from work and we went to Bible college for 2 years. It was fantastic, I was exposed to so much about my faith and that of others, spent hours trawling through the library, learned loads about my faith, came to understand why I believe what I do. We went to a large charismatic baptist church at first, and when we moved house within the city, to a smaller community based baptist church.
My extended family are no longer Christian in an active sense, though my sil is Catholic, and my nephew was baptised. Dh's mother and brother/SIL are Christian, bil&sil also went to bible college, but in Canada.
I think I am what I am (I describe myself as "Christian" but as you can see I'm happy in any denomination - and though I wouldn't be a member of some Protestant churches or he Catholic Church, I'm quite happy to worship with other Christians) due to upbringing but also due to interest and finding out about other faiths and faith expressions. Of course it's going to be culturally mediated, but the church I go to now doesn't look much like where I started out!