Quoting Minion:" I am not Christian, but most people I know are. My facebook newsfeed is constantly clogged with "Praise ... [snip!] ... comes (Oh and they know it's happening in our lifetime) I'll be left behind. And I'm dragging my daughter along with me."
I think if they are just opinions, don't stop! If they're insulting, that's different. I think that about religious posts though. It's one thing so post "praise Jesus," as it is to post "Gays are sinners and going to hell." Likewise, posting something non-religious is a-ok, but posting "Christians are followers who don't use their brain is rude.
You can be rude all you want though, just can't get too upset when people don't like it either. If you aren't being rude/disrespectful though then I think they need to STFU, because just like they are entitled to celebrating their faith you can celebrate your lack of faith (or a different faith) all you want too!