I just take them in stride. My children won't be deprived of things because of what I think just like I wont judge them for what they decide to beleive. Religion seems to be a choice and I've made my opinion known, but just like I ask, I wont push it on others.
You have just as much right to your belief as theirs. If they have a problem with respecting others' beliefs, agree to disagree, but don't let them take away your happiness. You also might want to remind them that Israel has one of the highest populations of Atheists in the world, and that it's OK to follow Jewish tradition without believing in sky monsters from the bronze-age. 25% of Canadians are also Atheist or non-theistic.
One of my parents is a hard-core religious fundamentalist, and I choose not to talk with that one. I get along just fine with the other. They pretty much live separate lives, kind of like roommates.
Hope this helps some. Take care.