There is a full pantheon of bloodthirsty gods to choose from when making whatever sacrifice you wish to make. One doesn't have to assume that any of them exist to ask why human beings feel that blood is spiritual currency. In fact, human beings believe that blood is spiritual currency despite the fact that the tax collectors themselves (those blood gods) don't actually exist, yours included. That scapegoating and blood sacrifice have no effect should be obvious. Firstly, what effect could they have? By what mechanism? To whom?
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!