[Is that a question posed as a statement? Ah well, Kaworu will answer. His face remains in a bland, mild smile as he explains:]
Angels exist to reunite with their creator, which would cause all the Lilim in the world to lose their physical form - they'd become a sort of sea of life, a return to the primordial soup, still living but without any form of division between them. Some of them, like the men I work for, want that, and some consider it tantamount to the apocalypse.
[A little more thoughtfully, but still with that odd smile.]
I'm the only Angel to take Lilim form and really interact with them and learn about them, instead of just destroying everything in the path between myself and Adam. That probably gives me a different outlook on things.