Lyin- someday maybe your fathers third daughter will leave the religion too. There's a good chance of that. Maybe that will wake your father up. At least if that happens you can have another sister and hopefully won't blame her for your fathers favoritism. He really sucks and you deserve better.
We all deserve better. we deserve parents who love us unconditionally. I wrote my mother recently a text, 'I love you' she wrote back 'thank you.'