First of all, I'd talk to all the people that have converted to a different religion and ask them if they're stuck. If you believe in something and it happens to coincide with a certain religion, then you should probably follow that religion.
If your parents instilled their morals and beliefs into you and those are you keep those belief as your grow older, why would there be any reason to change.
As people grow up they are influenced by the people and things around them. Nothing is more influential then ones parents. So people have a tendency to share their religious beliefs with their parents. But the way you tell it, it's as if that’s a bad thing.
I really don't know how to explain it to you. I'm not good at right what I think. But to say we are not given a choice is a very inaccurate statement.
Potato.