I only have an extension of your question, not an answer:
In Matthew 5:17 NIV, Jesus says:
"Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them."
This is practically the exact opposite of what Christians actually believe. I remember being taught in (my relatively liberal) church that Jesus transcended the specific laws and instead preached the two commandments of belief in god and love your neighbor as yourself. And that's why we don't follow the laws of the old testament.
I've always wanted to know how people who pick and choose from the old testament rationalize this passage.