Should I delete a Christian family member on Facebook who is bothering me?

Hi. I have a deeply Christian nephew who is causing me a bit of grief. But i don't want to delete him as it may cause friction with my already divided family. Here's the situation. Whenever i post something on Facebook that doesnt fall under what he feels is Christian-like,he writes sarcastic remarks. I posted a vid on Carl Sagan and he writes back and says that he is a evil New Age thinker,etc. I write that i'm going to see Bruno,and he says "youre watching gay .thats sick". I delete the remark. He writes back and says "i see you deleted my remark. Does that mean you believe in "gay rights"? you're going off the deep end,my friend " But the shocker is,is that he doesnt know i AM gay! So what do i do? If i delete him,the sh*t will hit the proverbial fan as my bro and his wife agree with what he's saying,im sure. But i can't let him post nasty,"fire and brimstone" remarks on my page that my mate's see. So what do i do? Thanks and have a good Sunday. X sarah