How can there be warriors when war is not supposed to be of the true light?

How can Michael be Michael, a shining beacon of justice, when in order to fight for something there has to be something to fight, but also, for someone to fight it. War itself is an inherent abomination, but at the same time it's a manifestation of fighting against yourself to better understand yourself. It's not about the slaughter. It's the learning experience. As gandalf implied to frodo...it wasn't pity that stayed your hand from killing gollum (it was fate) for he had another part to play in the story. The greatest warriors know when to push and when to pull back and lead by example. There are two examples to learn from, Michael (order), and Lucifer (freedom). What then happened is it devolved into Kaos/chaos. A free for all. Ego driving the self and putting the self above God (source). We stopped seeing each other as neighbors and saw each other as enemies instead. We forgot how to learn from one another. I'm guilty of that myself...there are many cultures on this world atm that I do not like, yet the preference I have for the western world is only because I have failed to see the goodness in the other side of it.