How do you get along with in-laws who seem to hate you?

Yesterday, my husband's family came over for my mother-in-law's birthday. Some days seem to last forever and they are never the days you enjoy. My in-laws seem to hate me, especially my sister-in-law. Everyone was in MY living room having a discussion about children, laws and such. They all seemed to agree children were all stupid and it is the public education systems fault and also that their civil liberties were being violated because you can't smoke in a lot of public places anymore (of course, they all smoke) and to them they are being persucuted like the Jews (which I think is hilarious). So they wanted total freedom to drive drunk(again some of them have DWIs), not wear seat belts, no child seats, smoke anywhere they want. So I said," Okay if you want total freedom without laws then same -sex marriage should be allowed and beating your children. (I do believe in freedoms that do not harm people should be allowed I'm not sure how I feel about same-sex marriage, but I would never believe child abuse is okay). Then, of course, my husband's sister starts screaming at me that no those things are wrong because the bible says their wrong. Which in turn, I calmly (yes, I did stay calm for my husband's sake only because this isn't the first time she has screamed at me) stated well if your using the Bible as your measurement some people interpet the bible to state beating your children is alright which she screamed the Bible doesn't state that. I then stated the passage in the Bible that states "spare the rod, spoil the child". I then try to explain that the Bible can be interpreted to mean many things by whoever is reading it. I also tried to explain that I was not trying to state every law we have are just laws, but that we are the people who vote for people and the only way to change things was to elect new people. She wasn't listening though, because she only thinks she is right. It is too bad that she can't or won't hear other people's opinions because I did agree with her that as long as you weren't blowing smoke in my or anyone else's face you should be allowed to kill yourself with cigarettes.