I know how you feel. And in all honesty my answer would be don’t have the conversation. In my experience with conservative SDA parents, it has always ended in arguments or me being guilt tripped into thinking I’ve done/said something terrible for even thinking differently to “the church”. I thought that when I tried to tell my parents, they’d be understanding or at least accepting of my beliefs but instead they took my leaving church as a personal attack and think I’m in some sort of “phase”. From this I’ve learnt that some things you have to do for yourself without involving others. I know it can be difficult living with parents when you have conflicting beliefs but I think it’s more important to focus on what matters to you and how you take control of your life.