People tend to think that children don't think for themselves, but that's not true. Children have personalities and they question things. Just because someone is brought up religious does not mean they will stay religious for the rest of their lives. However, how one is exposed or isn't exposed to religion does heavily impact their future beliefs.
People you grow up with can't control your thoughts, maybe influence it, but not control it. If you believe what they say, you've chosen your religion. If you don't believe what they say, but they're strict, you can lie that you believe in the religion they've attempted to teach you. Most people raised to believe in a religion would say they chose to believe in it, because in reality, it is their choice.