From what you say, it seems that we should kill them only if there's someone without sin to cast that stone, right?
But don't ask me...I'm not Christian--I support capital punishment.
In any case, that's off-topic. The point is, if you're wanting to convert them, to what should they be converted? As I pointed out in earlier posts, the idea of killing those who don't convert is simply not Christianity. It sounds more like Islam, and that's their current religion.
"Wanting to convert them" is not an option for those who profess to love the living God and their neighbor. His Son commanded us to make disciples - to teach the nations the truth about His Father. My point is that Jesus taught that those who don't accept this truth (or convert, if you like) will die. Nothing controversial there - it is a fundamental tenet of Christianity.