Religious conflict in household. Help!
My older sister has been an ardent atheist in a very religious household for about 8 years. As a result, she and my mom, a strong believer, have been at each other's throats almost the entire time. It was especially bad near the beginning of the 8 years when my sister was a teenager. Back then, just about every Sunday was interlaced with snarky quips and incessant arguments. Both my mom and my sister were very hostile towards each other and both have very simplistic views in order to justify the constant contention. My mom thought that my sister was under the influence of Satan and that she was going to lead me and my brothers astray while my sister, in standard teenage fashion, thought that the world was against her and nobody understood what she was going through. Both of them have reasons for arguing that I empathize with; my mom wants what's best for her kids and my sister wants to be accepted for who she is and what she believes in a community where that can be difficult (my family members are Utah Mormons, by the way). Fast forward a few years and my sister is 25 and still living at home. She and my mom have made enough progress so that they can coexist, more or less. Unfortunately, the way they do that is by leaving each other alone and essentially ignoring each other when they are together. Even after 8 years you can feel the tension and the resentment between them when they come into contact with each other and I can't help feeling like this type of relationship isn't sustainable let alone healthy. Occasionally, one of them will make some snide remark at the other and start a conflict. Both like to pretend like the other is solely responsible for these quarrels when both of them are responsible. In addition to the religious issues, my sister will disappear for long stretches of time and say that she was just out tanning: an obvious lie. Naturally, my mom worries about where she's been because she still lives at home and she feels like she's responsible for our safety as long as we live at home. My mom wants to know if my sister is safe and my sister wants to be treated like an adult which causes more contention and frustration. As for me, I'm an agnostic but I still go to church so as to not end up in the same place as my sister. Sad right? I'm basically living a lie so that I can stay on good terms with my mom. I'm also in a predicament because I can see both sides of the problem but because of my sister's and mom's "us them" mentality it makes it hard for me to say anything with out one of them attacking me for being moderate. I honestly think that it would be good for my sister to move out but I would also like them to be on good terms before parting. I've tried to talk to them about how they could mend their relationship but when it looks like they might actually sort out their differences it just devolved into a fight. I don't know what to do. Any thoughts or tips?