Alvin York was something of a rambunctious bad boy in rural Tennessee who got religion and tried to dodge the draft in 1918 by claiming Conscientious Objector status. The draft board denied his petitions and appeals, and he was drafted for service in WW1.
His religious fervor conflicted with his "duties" as a soldier in the US Army, and since cognitive dissonance generally moves an individual to change his behavior and/or his thinking, Alvin did what most every young man does who gets hammered every day with military training and indoctrination - he (more or less) simply rationalized his way into thinking god wanted him to be a good little soldier, and of course, that led him to alter his beliefs enough to view the German soldiers as a line of turkeys that he then proceeded to shoot one-by-one in the back - and that makes him a true American hero and we all wish we could grow up to be just like him.