Raising kids in a secular world feels impossible sometimes

Between school, friends, social media, and just general culture, feels like everything is working against what we're trying to teach them about faith and values. My 11yo came home asking why Christians believe different things than his friends' families. Instead of getting defensive I tried to explain why we make the choices we do but I'm not sure it landed. How do you guys help your kids actually own their faith instead of just adopting what mom and dad believe? I want them to choose this for themselves but I also want them grounded in truth.