THE GENERIC ANGEL THEORY
generic angels, believe it or not... ARE able to love or hate...they just need to realize it first. They are created into a world where questioning their master (God) is never a thought in their mind...

they only serve as purified slaves...and only few are able to realize that they are able to think for themselves...thus they have commited a 'sin' and are pushed out of heaven and onto earth. So, they exist on earth...not as the pure angel they once were... but also not as a human. No soul, but they are still able to love and hate.