Do my parents fear that I'll leave the faith?

[Der/die AtheistIn]

I'm already atheist and I haven't told them yet. Sometimes I wonder if they're sure I'm a believer, if they fear that I only pretend to believe, or that I'll someday leave the faith. When I told my mom I had some doubts about the faith, she insisted that faith is good and I should stay, even though I didn't say I want to leave. She was speaking calmly and gently, but I felt like she was fearing and didn't want to exteriorize it. Dad is also pretty insistent about faith. My parents don't believe in Hell, so it can't be that. What they fear is that I will not follow the herd like a good sheep and life would be harder for me as a minority. 
My question is: are they sure I'm a believer? Can I find the answer without asking them?

Also, Happy Holidays! For those who celebrate them and if you don't, then Happy Nonholidays! or Happy Commercialdays!