These people are morons lead by religiously incompetent preachers.
The whole point of that passage from the bible is everyone has sinned, therefore everyone is a sinner and must repent.
Just because you repent does not mean you are sin free, and therefore should not be casting stones.
I was raised Church of England, which is a Christian denomination that has a comparatively light touch when it comes to theological teachings and EVEN I know that!
My father in law is one of these wackos. I think he is on his 5th or 6th wife. His daughter has been married to me longer than all of his marriages combined.
It's the reward for piousness. You can sin all you want, as long as you pray for forgiveness and give yourself over to Jesus. Then you are washed clean of sin. The other person that didn't immediately admit their sins and pray for forgiveness enough...they are sinners that deserve to be stoned.
A seemingly large number of Christians simultaneously claim they are not beholden to the old testament cause that's between Jewish people and God, and also claim that all this hateful shit they cherry pick and misinterpret from the Old Testament must be carried out today cause it's in the Bible.