Christian salvation consists in works. To be saved is to be made holy. To be saved requires our being made part of a people separated from the world so that we can be united in spite of - or perhaps better, because of - the world's fragmentation and divisions.
Being a Christian has not and does not come naturally or easy for me. I take that to be a good thing because I am sure that to be a Christian requires training that lasts a lifetime.
I think it is a mistake to focus - as we most often do - only on the sacrifice of life that war requires. War also requires that we sacrifice our normal unwillingness to kill.