Fact is people that are filled with so much hate can never really be changed, you can use all the facts and logical arguments you want but it won't change much of anything. If your parents are these people than I would suggest you just wait until your old enough or have enough money and then move out on your own, as far away from them as you can. I know they are still your parents, so long as you aren't gay because like you said they'll disown you if you are, and none of us here can stop you from loving them, so don't cut off contact completely. Just stay at a safe distance from all that stupidity and close mindedness, I'm sure that will do you wonders.
Thankfully I grew up in a household where I was allowed to think what I want about any topic, even Santa Clause wasn't thrown in my face as a child, and I'd say I came out pretty good from that envioronemnts. So for the love of god man, if you ever have kids please don't raise them the same way you were