I agree with some of the other posters that you should shower them with love and let them make up their own minds.
Any way you slice it, you've got a tough row to hoe. I guess the one thing to be very cautious about is to avoid any suggestion of hypocrisy or double standards when it comes to observing holidays...maybe not over-do it either...just stay balanced and hopefully they will see the merit in your stance.
Cheers,
Alex