Ouch, that's a rough situation. My parents have always been open to allowing me to believe whatever I wanted so I can't draw on my own situation for advice. I would try explaining to them that they have their beliefs and you as a separate individual should be able to have your own. I would stick to my guns to that and let them know that they need to accept it. If that doesn't work you could just fake it to get them off your back.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell
