A lot of the rules in the old testament were nullified by the coming of Christ. That’s why I shave and wear synthetic clothing and don’t kill people for disrespect. It’s not because I selectively believe what I want to. On the other hand some are still kept, such as the things God says about marriage and the story of creation. It’s not clear just from reading Leviticus what is and isn’t still applicable, but by reading the New Testament the differences come out. So go ahead and make fun of Jews for burning cows (since they do believe that), but please, make fun of me for the things I actually believe.

A couple of minor points:
– The age of the earth as having been created in 4004BC (as I assume that’s what you’re referring to) is wrong. There are gaps in the biblical genealogies so the guy who calculated that number was incorrect. I don’t believe that the earth is billions of years old, however – if you want to know why, let me know and I’ll explain on my blog.
– _Hatred_ of homosexuality justified from the Bible is wrong. I believe homosexuality is wrong but I don’t hate homosexuals. I could also write more on this.

To argue a moral stance by using bible verses when you are talking to someone who doesn’t believe in the bible is ridiculous.