Temporary death? Well, Kaworu can't say that's new, given his own body has been cloned plenty of times in order to salvage his soul (and also to use the bodies to control giant robots, but that's a whole different matter). But he knows how much Lilin fear death, how much they want to hold on to the idea of an eternal life where death does not exist.

"If you have not killed anyone, how were you accepted?"