This battle is the battle for making God and His ways work in your life from day to day while THEY are fighting out the big one on the cosmic scale.
Faith is the ability to be flexible in the unknown.
Most of life is made up of the unknown. Not everything is crystal clear and direct from God. Most of the time I have to be willing to trust and not doubt that He is leading because I can't always see the way through from start to finish. This goes contrary to our natures. We want the answers and we want the solutions and we want them now.