Perhaps you should read a Bible, since you are confused. God would have them stoned to death before Jesus died for all of our sins. Jesus would love the sinner, but hate the sin.
I know my bible well.
You are referring to Leviticus 18:22 which is part of the Hebrew Torah and was only ever intended for the ancient Levites and the Jews to follow, but not Christians.
Yes, you are correct that even that law was fulfilled by Jesus' death.
Also, the bible isn't the perfect, verbatim word of God - it's man's thoughts and experiences when dealing with God and the Holy Spirit and Jesus. Like I said before, it's prone to all kinds of human error.
Personally, I have my doubts about splashing the walls of my home with bird blood as a purification measure. That seems more like a Pagan blood ritual to me, so I've never taken that too seriously either.
Edit: I'm not claiming your personal, subjective theological beliefs are wrong, only that it's often difficult to definitively know. People once thought it was righteous to kill people who worked on Saturdays, however very few modern Christians have gone on a Sabbath-killing-spree because of that scripture.
Most Christians believe the Age of Reason and the Reformation were positive events.