Why do Atheists literally fabricate fallacies about Christianity?

I'm not sure why Atheists feel that they have to try to ruin the joy and happiness that we have discovered in the Lord. But, in opposition to some of the comments made here, I would like to say that I have read the entire Bible, I know what it says, and I know for sure that God does NOT condemn sexual intercourse in anyway. He says that sex outside of marriage should be avoided and that if sexual intercourse is getting in the way of worshipping the Lord or loving others, then that is a problem. However, sex in itself is not sinful within marriage.